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PRESENTED  TO  THE 


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Library  of  the  University  of  California,  I 


40TH  CONGRESS,  \  SENATE.  (  EEP.  COM. 

3d  Session.       (  )    No.  266. 


IN  THE  SENATE  OF  THE  UNITED  STATES. 


FEBRUARY  15,  1869. 

FEBRUARY  25,  1869. — Ordered  to  be  printed,  and  that  two  thousand  additional  copies  be 
printed  for  the  use  of  the  Senate. 


Mr.  HOWARD,  from  the  Joint  Committee  on  Ordnance,  submitted  the 

following 

,,          EEPORT.      *  ' 

The  Joint  Committee  appointed  under  the  resolution  of  the  Senate  and 
House  of  Representatives  of  the  30th  of  March,  1867,  to  investigate  the 
purchases,  contracts,  and  experiments  of  the  ordnance  department,  having 
completed  their  labors  as  far  as  relates  to  experiments  upon  heavy  ordnance, 
submit  the  following  report  thereon: 

Since  the  war  of  1812  there  has  been  a  tendency  on  the  part  of  all 
nations  to  increase  the  size  of  their  artillery,  and  within  the  last  few 
years  the  important  change  made  in  systems  of  defence  by  the  intro- 
duction of  armor-plating,  necessitating  more  powerful  engines  of  attack, 
has  resulted  in  enormously  increasing  the  -weight  and  calibres  of  guns. 
This  increase  of  calibre  early  developed  a  remarkable  and  puzzling  fact, 
namely,  that  systems  of  fabrication  which,  with  small  calibres,  gave 
good  endurance  when  applied  to  large  guns,  proved  to  be  failures. 
Elaborate  experiments,  stretching  over  a  period  of  years,  have  been 
carried  on  in  Europe  and  America  to  solve  this  problem,  and  many  new 
systems,  which  in  theory  promised  success,  have  been  successively  tried 
and  abandoned;  nearly  all  of  them  succeeding  well  in  small  guns,  but 
failing  in  large  ones,  and  failing,  too,  in  a  manner  which  apparently 
increased  the  complication  of  the  problem — a  gun  frequently  enduring 
over  2,000  rounds,  while  another,  precisely  similar,  would  explode  after 
a  few  fires ;  while  guns  made  of  the  strongest  material  seemed  generally 
to  prove  the  weakest  when  put  to  the  test.  No  nation  at  present  has 
guns  of  large  calibre  the  endurance  of  which  can  be  estimated  with  any 
degree  of  certainty.  The  difficulty,  serious  enough  with  smooth-bore 
guns,  is  greatly  increased  in  rifles,  the  30-pounder  being  the  largest  rifled 
gun  that  has  exhibited  even  comparatively  good  endurance  in  this  coun- 
try, while  in  Europe  no  more  satisfactory  result  has  been  obtained. 

This  unreliability  of  heavy  ordnance,  from  its  tendency  to  rupture, 
has  been  heretofore  supposed  to  be  attributable  wholly  to  the  expan- 
sive or  projectile  force  of  the  powder  undergoing  combustion,  and  the 
efforts  of  inventors  have  been  directed  to  devising  new  means  the  better" 
to  restrain  this  force,  and  on  failing,  it  has  been  common  for  them  to 
attribute  enormous  pressure  to  the  gases  of  the  powder  in  order  to 
account  for  the  bursting  of  the  guns ;  but  the  fallacy  of  this  reasoning 
is  shown  by  the  fact  that  the  pressure  of  powder  has  been  found  to  be 
uniform,  as  it  gives  uniform  range  to  the  projectile,  and  at  times  does 
not  burst  a  gun  made  of  weaker  material  than  others  which  have  burst 


2  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

when  fired  with  like  charges  and  under  like  circumstances.  Acting 
upon  this  mode  of  reasoning,  two  means  of  increasing  the  strength  of 
the  gun  so  as  to  restrain  the  force  of  the  powder  have  been  employed ; 
the  use  of  stronger  material,  such  as  steel  and  wrought  iron,  and  methods 
of  fabrication  which  secure  a  compressing  tension  in  the  metal.  Both 
of  these  means  are  employed  in  the  English  Armstrong,  Fraser,  Whit- 
worth,  and  Blakely  guns,  while  in  the  Krupp  guns  of  Prussia,  the 
strength  of  the  metal  (steel)  is  alone  relied  on,  and  in  the  Rodman  hol- 
low-cast guns  of  this  government  tension  is  the  restraining  force  chiefly 
sought.  These  two  principles  have  been  embodied  to  a  greater  or  less 
extent  in  all  the  various  systems  in  this  country  and  Europe  since  the 
solid  mode  of  casting  was  abandoned  in  our  service  for  the  hollow  mode 
introduced  by  Eodman  for  cast-iron  guns;  since  which,  in  this  country, 
reliance  has  been  placed  upon  cast  iron  with  initial  tension  from  the 
mode  of  cooling  the  gun,  or  cast  iron  banded  with  wrought  iron,  as  in 
the  Parrott  gun.  In  England  the  same  theory  was  introduced  in  the 
Armstrong  and  Whitworth  guns,  using  wrought  iron,  or  a  combination 
of  wrought  iron  and  steel,  in  built-up  guns,  and  cast  iron,  wrought  iron, 
and  steel  in  various  combinations,  as  in  the  Blakely  system.  Krupp,  of 
Prussia,  has  made  solid,  dense,  and  homogeneous  guns  of  large  calibre 
of  steel  alone,  yet  his  very  largest  guns  have  been  built  up  also. 

None  of  these  systems  have  proved  successful  in  preventing  the  burst- 
ing of  guns,  or  giving  them  uniformly  reliable  endurance.  The  com- 
mittee do  not  think  it  necessary  to  discuss  further  the  various  European 
systems  of  gun-making.  None  of  them  have  shown  exemption  from  the 
rule  of  failure,  and  experiments  with  them  on  the  part  of  this  govern- 
ment would  be  of  doubtful  value.  The  Rodman  system,  employing  cast 
iron,  has  had  the  merit  of  cheapness,  and  when  applied  to  smooth-bore 
guns  has  had  claimed  for  it  superiority  over  European  sytems,  but  it 
must  be  considered  to  be  equally  a  failure  with  the  others,  especially 
when  applied  to  rifled  guns.  The  Chief  of  Ordnance  of  the  navy,  in  his 
last  report,  acknowledges  this  to  be  the  case.  He  says: 

Opinions  differ  quite  as  widely  in  regard  to  the  preferable  mode  of  developing  ordnance 
power,  whether  it  shall  be  by  smooth  or  rifled  bores,  by  loading  at  breech  or  muzzle,  made 
from  iron,  cast  or  wrought,  or  from  steel,  solid  or  in  connected  parts.  The  relation  of  mass 
to  velocity  is  also  unsettled.  In  fact,  the  question  involves  the  necessity  of  going  back  to 
fundamental  principles,  and  starting  thence  by  well-conducted  experiments. 

It  therefore  appears  that,  notwithstanding  a  series  of  elaborate  experi- 
ments, extending  over  a  long  period  of  years,  and  the  practical  experience 
of  our  recent  war,  the  ordnance  officers  of  the  government  have  not  yet 
determined  upon  even  the  fundamental  principles  of  their  art,  and  possess 
no  positive  knowledge  of  the  problem  they  have  so  long  sought  to  solve. 
Mechanics  is  an  exact  science,  and  ignorance  of  that  branch  of  it  involved 
in  the  construction  of  guns  Avould  seem  to  show  either  want  of  knowledge 
of  its  principles,  failure  to  understand  their  application,  or  superficiality 
of  investigation,  surprising  in  men  whose  minds  have  been  from  boyhood 
trained  in  the  direction  of  a  specialty. 

Each  system  of  guns  introduced  in  our  service  has  been  subjected  in 
proof  to  tests  supposed  to  demonstrate  beyond  question  its  ability  to 
perform  the  work  required  of  it,  but  each  has  failed  when  submitted  to 
the  real  test  of  service.  In  the  operations  upon  Morris  island  22  large 
guns  was  the  greatest  number  mounted  at  one  time,  yet  50  in  all  burst 
during  the  siege,  as  is  shown  by  the  evidence  of  General  Gillmore.  In  the 
attack  on  Fort  Fisher  all  the  Parrott  guns  in  the  fleet  burst,  according 
to  the  report  of  Admiral  Porter.  By  the  bursting  of  five  of  these  guns 
at  the  first  bombardment  45  persons  were  killed  and  wounded,  while 
only  11  were  killed  or  wounded  by  the  projectiles  from  the  enemy's  guns 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  3 

during  the  attack.  The  battle  of  Fort  Fisher  was  the  only  occasion 
during  the  war  when  rifled  guns  of  large  calibre  were  fired  rapidly  and 
continuously  for  a  great  number  of  rounds. 

The  failure  to  discover  the  weakness  of  these  guns  before  putting  them 
in  the  field,  or  on  board  ship  for  actual  service,  must  be  attributed  to  a 
defect  in  the  system  of  proof  employed.  These  systems  appear  to  have 
been  comparatively  valueless,  and  to  have  proven  little  or  nothing  re- 
specting the  ability  of  the  gun  to  perform  the  work  expected  of  it  in 
battle.  The  committee  cannot  learn  that  any  method  of  proof  has  been 
practiced  in  the  army  or  navy  which  subjects  guns  to  the  tests  they  must 
endure  when  first  brought  into  actual  combat,  namely,  rapid  and  con- 
tinuous firing,  with  intervals  only  sufficient  for  loading.  Excessive 
charges  have  been  used  and  a  great  number  of  rounds  fired,  but  no  at- 
tempt has  been  made  to  copy  upon  the  proving  ground  the  conditions 
existing  in  battle.  In  the  new  conditions  developed  by  the  rapid  and 
long-continued  firing  in  battle,  not  present  during  the  slow  and  careful 
firing  when  in  process  of  proof,  it  would  seem  must  be  found  the  cause 
of  the  frequent  rupture  of  the  guns.  The  most  important  new  condition 
present  during  rapid  fire  would  seem  to  be  the  communication  of  a 
greater  amount  of  heat  to  the  bore  of  the  gun,  having  a  tendency,  by  its 
expansive  force,  to  aid  the  powder  in  effecting  a  rupture.  If  the  gun 
be  fired  rapidly  so  as  to  allow  little  time  for  the  bore  to  cool  between 
each  discharge,  it  is  believed  that  the  heat  communicated  would  exert 
a  powerful  expanding  force ;  while  if  there  should  be  long  intervals 
between  the  shots,  even  if  the  charges  were  excessive,  sufficient  heat  to 
burst  the  gun  might  not  be  communicated  to  the  interior.  In  reports  of 
ordnance  officers,  the  effect  of  unequal  cooling  in  inaugurating  unfavor- 
able tensions  in  a  gun  cast  solid  and  cooled  wholly  from  the  outside 
is  treated  at  length,  and  it  is  shown  that  fissures  and  ruptures  have 
resulted  from  the  contraction  towards  the  outside  as  the  gun  cooled, 
and  it  is  stated  that  three-fifths  of  the  strength  of  the  gun  is  ex- 
pended in  this  manner,  leaving  only  two-fifths  to  restrain  the  pressure 
of  the  powder.  The  hollow  mode  of  casting  of  the  Eodnian  system, 
and  the  band  of  wrought  iron  applied  to  the  Parrott  gun,  were  in- 
tended to  utilize  this  force  of  contraction,  by  assisting  the  strength 
of  the  iron  to  restrain  the  pressure  of  the  powder.  It  was  afterwards 
noticed  that  several  of  the  Eodnian  guns  casfc  hollow,  and  cooled 
from  the  interior,  burst  in  the  foundry  from  the  excess  of  this  force 
of  contraction  exerted  in  the  opposite  direction  from  that  before 
referred  to.  If  the  force  with  which  metals  contract  when  cooled  is 
shown  to  be  so  potent  as  to  break  the  gun  from  the  inside  when 
cooled  from  the  outside,  and  from  the  outside  when  cooled  from  the 
interior,  it  can  be  seen  that  if  the  gun  be  in  a  state  of  tension,  which 
has  the  tendency  to  compress  the  metal  of  the  interior  and  extend 
the  exterior,  the  heat  afterwards  communicated  to  the  surface  of  the 
bore  by  the  burning  powder,  or  by  friction  of  the  moving  charge,  would 
assist  the  pressure  of  the  powder  to  break  the  gun,  especially  if  the  gun 
should  be  fired  a  number  of  rounds  in  quick  succession.  This  additional 
force  being  considered,  it  may  be  possible  to  determine  why  guns  made 
of  the  strongest  material  are  more  liable  to  burst  than  those  made  of 
weaker  iron,  and  why  the  accidents  occur  most  frequently  during 
battle,  when  the  gun  is  fired  more  rapidly  than  at  the  time  of  proof, 
when  it  is  usually  fired  slowly.  Forces  known  to  be  sufficient  to  actu- 
ally break  large  masses  of  iron,  spontaneously,  as  it  were,  should  not  be 
overlooked  while  treating  so  intricate  a  subject  as  this  of  heavy  guns. 
Mr.  Holley  refers  to  the  rupture  of  a  large  mass  of  wrought  iron  pre- 


4  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

pared  by  Mr.  Mallet,  in  England,  as  attributable  to  "  the  force  of  con- 
traction from  the  centre  toward  the  exterior  as  the  mass  cooled."  Such 
ruptures  of  large  steamboat  shafts  are  frequently  noticed,  and  con- 
traction of  this  kind  may  explain  the  fissures  in  large  wrought-iron  guns 
which  have  been  noticed,  as  well  as  the  soft  and  easily  compressed  nature 
of  the  iron  in  the  interior  of  the  mass  of  all  classes  of  large  guns. 

The  fact  that  the  ordnance  officers  of  the  government  find  it  necessary, 
at  this  late  day,  to  return  to  the  sudiments  of  their  art  and  begin  their 
experiments  anew,  as  stated  in  the  report  of  the  Chief  of  Ordnance  of  the 
navy,  shows  a  defect  in  the  system  upon  which  experiments  have  heretofore 
been  conducted,  and  in  the  organization  of  the  ordnance  departments,  call- 
ing for  a  remedy.  The  difficulty  appears  to  have  been  two-fold  :  First,  the 
ordnance  officers,  knowing  their  positions  secure  to  them  for  life,  have 
not  felt  the  incentive  to  exertion  and  improvement  which  stimulates  men 
not  in  government  employ,  and  they  have  become  attached  to  routine 
and  to  the  traditions  of  their  corps,  jealous  of  innovation  and  new  ideas, 
and  slow  to  adopt  improvements.  An  illustration  of  this  is  found  in 
the  fact  that  the  late  war  was  fought  with  muzzle-loading  guns,  (with 
the  exception  of  carbines  for  cavalry,)  although  a  variety  of  excellent 
breech-loaders  were  urged  upon  the  attention  of  the  government  con- 
stantly, and  the  honor  Avas  reserved  for  Prussia,  with  a  weapon  inferior  to 
many  American  inventions,  to  demonstrate  the  immeasurable  superiority 
of  breech-loading  guns.  In  the  second  place,  these  officers,  educated  to  a 
specialty  and  proud  of  their  positions,  come  to  look  upon  themselves  as 
possessing  all  the  knowledge  extant  upon  the  subject  of  ordnance,  and 
regard  citizen  inventors  and  mechanics  who  offer  improvements  in  arms 
as  ignorant  and  designing  persons,  and  pretentious  innovators,  who 
have  no  claim  to  consideration.  Instead  of  encouraging  the  inventive 
talent  of  the  country,  these  officers  seem  to  have  constantly  discouraged 
it,  and  many  complaints  of  improper  and  oppressive  treatment  have 
been  laid  before  the  committee  by  persons  who  have  sought  to  draw  the 
attention  of  the  proper  authorities  to  what  were  supposed  to  be  vital 
principles  connected  with  their  art.  Another  difficulty  that  has  retarded 
progress  in  the  science  of  ordnance  has  been  the  fact  that  prominent 
officers  have  been  inventors  of  arms,  and  have  possessed  sufficient  influ- 
ence to  secure  the  adoption  arid  retention  in  service  of  their  inventions, 
frequently  without  due  regard  to  the  question  of  real  merit,  and  to  the 
prejudice  of  other  and  better  devices  brought  forward  by  citizens,  or 
developed  in  other  countries.  A  further  difficulty,  calling  for  a  remedy, 
lies  in  the  want  of  co-operation  between  the  war  and  navy  ordnance 
bureaus.  Great  diversity  exists  in  the  practice  of  the  two  branches  of 
the  service  respecting  the  arms  adopted,  and  the  manner  of  proving, 
mounting,  and  using  the  same.  The  calibres,  models,  chambers  and 
ammunition  of  the  navy  guns  are  entirely  unlike  those  in  use  in  the 
army.  For  example,  the  navy  12-pounder  boat  howitzer  has  a  calibre 
of  3.4  inches,  while  the  army  12-pounder  guns  are  of  the  calibres  of  3, 
3.2,  3.67,  and  3.8  inches.  The  chamber  of  the  navy  gun  is  of  parabolic 
form,  while  the  army  gun  either  has  a  cycloidal  chamber  or  none  at  all. 
The  models  of  the  two  guns  are  entirely  different,  so  that  neither  could 
be  used  on  the  carriage  of  the  other;  the  army  guns  being  furnished 
with  trunnions,  and  the  navy  gun  having,  in  some  cases,  the  loop 
and  loop-bolt  of  the  old  carronade.  The  system  of  sighting  is  also 
different.  A  gunner  in  one  arm  of  the  service,  without  special  instruc- 
tion, could  not  use  a  gun  belonging  to  the  other;  one  being  grad- 
uated to  seconds  of  time  of  the  flight  of  the  shot,  and  the  other 
to  degrees  of  elevation.  The  navy  has  8,  9,  11,  and  13-inch  smooth 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  5 

bores,  while  the  army  guns  are  of  the  calibres  of  6,  8,  10,  and 
12  inches.  In  the  guns  of  the  two  branches  of  the  service  there 
is  no  uniformity,  in  either  rifle  or  smooth-bore,  in  the  20  calibres 
adopted  below  the  calibre  of  the  32-pounders.  It  is  impossible  to 
use  navy  ammunition  in  an  army  gun  or  army  ammunition  in  a  navy 
gun.  Co-operation  between  the  army  and  navy  while  in  active  service 
is  thus  greatly  restricted,  and  in  some  cases  has  been  entirely  prevented. 
Offensive  operations  on  the  part  of  a  joint  expedition  of  the  two  might 
be  brought  to  an  end  by  the  want  of  projectiles  for  the  land  forces,  while 
the  ships  of  the  navy  possessed  a  surplus  of  the  very  articles  required, 
which  could  not  be  used  by  the  land  forces.  Not  a  single  advantage 
is  claimed  for  this  lack  of  uniformity,  while  the  disadvantages  are  very 
numerous  and  apparent.  It  has  grown  out  of  the  fact  that  officers  in 
the  two  branches  of  the  service  have  succeeded  in  securing  the  adoption 
of  their  own  inventions,  and  the  rivalry  existing  between  them  has  pre- 
vented fair  competitive  trials  of  the  various  devices  and  systems  advo- 
cated by  each,  neither  being  willing  to  admit  the  merit  of  the  other's 
inventions,  or  to  utilize  the  knowledge  gained  either  by  their  successes 
or  failures.  The  experiments,  being  duplicated  on  account  of  this  jeal- 
ousy, have  been,  necessarily,  needlessly  expensive.  A  further  increased 
expense  results,  in  time  of  war,  from  maintaining  two  separate  organiza- 
tions for  the  procurement  of  arms.  The  two  ordnance  departments  are 
brought  into  competition  with  each  other  in  the  matter  of  contracts  and 
purchases  of  war  material  from  the  private  workshops  and  factories  of 
the  country,  thus  putting  the  government  in  the  attitude  of  bidding 
against  itself. 

The  investigations  of  the  committee  lead  them  to  the  following  con- 
clusions : 

1.  That  no  more  heavy  guns  should  be  purchased  for  mounting  in  the 
fortifications  or  use  on  shipboard  until  such  improvements  are  made  in 
methods  of  fabrication  as  will  insure  more  reliable  endurance  than  has 
heretofore  been  exhibited. 

2.  That  the  Rodman  system  of  gun-making,  while  partially  successful 
in  smooth-bores  and  small  calibres,  has  so  far  failed  in  rifles  of  large  cali 
bre  as  to  show  it  to  be  unworthy  of  further  confidence.    Recent  improve- 
ments in  defensive  works  and  armor-plating  render  heavy  rifled  guns  the 
most  efficient  means  of  attack,  and  no  system  of  fabrication  which  does 
not  furnish  such  guns  should  be  adopted  or  continued.    The  principle  of 
initial  tension,  which  is  the  basis  of  the  Rodman  system,  appears  to  be 
of  doubtful  utility,  as  applied  by  General  Rodman,  especially  for  rifled 
guns.    This  tension,  it  is  admitted,  gradually  disappears  from  the  gun 
with  age,  and  in  time  is  entirely  lost. 

3.  That  guns  cast  solid,  in  the  manner  practiced  in  the  navy  under 
the  direction  of  Rear- Admiral  Dahlgren,  while  exhibiting  satisfactory 
endurance  as  smooth-bores  with  small  charges  and  hollow  projectiles, 
have  not  the  requisite  strength  for  rifles  of  large  calibre.    This  mode  of 
casting  seems  to  be  defective  in  principle,  as  the  tensions  inaugurated 
in  cooling  have  a  tendency  to  aid  the  powder  to  rupture  the  gun. 

4.  That  experiments  should  be  at  once  conducted  for  the  purpose  of 
ascertaining  the  real  cause  of  the  bursting  of  heavy  guns,  and  of  deter- 
mining upon  some  method  of  fabrication  that  will  secure  uniform  endu- 
rance. 

5.  That  every  encouragement  should  be  given  to  inventors,  and  a  full 
and  fair  trial  accorded  to  all  devices  offered  to  the  government  that 
promise  a  solution  of  the  ordnance  problem. 

6.  That  more  efficient  means  for  harbor  defence  should  be  adopted. 


6  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

The  late  war  demonstrated  that  sand  was  the  best  material  for  defensive 
works,  and  that  forts  of  masonry,  such  as  we  have  now  mainly  to  rely  upon 
for  the  protection  of  our  seaboard  cities,  are  inefficient  to  prevent  the 
passage  of  armored,  or  even  wooden,  vessels.  The  destruction  of  such 
defences  is  only  a  question  of  time  to  ordinary  guns  of  heavy  calibre. 
It  was  also  demonstrated  that  forts  alone,  of  whatever  character,  can- 
not resist  the  entrance  to  harbors  of  powerfully  armed  ships  if  the  pre- 
ponderance of  guns  on  the  assailing  fleet  is  sufficient.  In  the  opinion 
of  the  committee,  obstructions  must  be  largely  relied  upon  for  harbor 
defence,  in  connection  with  properly  constructed  fortifications. 

7.  That  no  officer  of  the  army  or  navy  should  be  allowed  to  receive  a 
patent  for  any  article  required,  or  likely  to  be  required,  for  use  in  those 
branches  of  the  public  service,  or  to  be  in  any  way  interested  in  the 
manufacture  or  procurement  of  such  articles.    It  should  be  the  duty  of 
Congress  to  recognize  by  suitable  rewards  the  services  of  such  officers 
as  might  make  inventions  of  especial  value  to  the  government. 

8.  That  the  ordnance  department  of  the  army  can  be  entirely  abolished 
with  great  advantage  as  to  economy,  and  without  detriment  to  the  good 
of  the  service.    The  duties  now  performed  by  officers  of  that  corps  could 
be  performed  by  officers  detailed  from  the  artillery  service,  under  the 
direction  of  a  chief  stationed  at  Washington.    In  this  manner  the  whole 
expense  of  the  ordnance  establishment  would  be  saved,  and  artillery 
officers,  who  have  not  only  scientific  training  but  practical  experience, 
would  have  a  voice  in  the  selection  of  the  guns  and  ammunition  they 
are  required  to  use. 

The  committee  are  of  the  opinion  that  for  the  reasons  shown  the  inter- 
ests of  the  public  service  demand  a  change  in  the  system  of  procuring 
ordnance  and  ordnance  stores,  and  the  manner  of  conducting  experiments 
with  a  view  to  determining  the  value  of  the  same.  The  present  system 
has  failed  to  answer  the  purpose  for  which  it  was  designed,  and  the 
TJnited  States  is  in  the  position  to-day  of  a  nation  having  a  vast  coast- 
line to  defend,  and  a  large  navy,  without  a  single  rifled  gun  of  large 
calibre,  and  a  corps  of  ordnance  officers  who  have  thus  far  failed  to  dis- 
cover a  remedy  for  the  failure  of  the  guns,  or  to  master  the  rudiments 
of  the  science  in  which  they  have  been  trained  at  the  public  expense. 
The  importance  of  an  immediate  change  is  shown  by  the  fact  that  the 
Chief  of  Ordnance  of  the  army  asks  for  appropriations  to  purchase  over 
1,900  guns  to  arm  the  forts,  not  of  a  new  and  better  system,  to  be 
decided  upon  after  more  thorough  and  careful  experiment,  but  of  a 
kind  that  experience  has  shown  to  be  inferior  in  range  and  penetration 
to  the  guns  of  foreign  powers,  and  unreliable  as  to  endurance. 

It  is  proposed  that  85  of  these  guns  shall  be  smooth-bores  of  20-inch 
calibre,  490  of  15-inch  calibre,  and  600  of  13-inch  calibre.  The  experience 
of  all  nations  goes  to  prove  that  the  most  effective  way  of  developing 
ordnance  power  is  by  rifled  guns.  To  return  to  smooth-bores,  throwing 
huge  spherical  masses  of  iron  with  low  velocities,  is  to  disregard  all 
modern  progress  in  the  science  of  gunnery,  and  to  go  back  to  the  arm  sin 
use  two  centuries  ago.  Furthermore,  the  advisability  of  using  guns  of 
such  great  size  is  very  doubtful,  for  the  slowness  with  which  they  can  be 
handled  and  fired  makes  them  less  effective  than  smaller  guns  delivering 
a  more  rapid  fire.  Two  hundred  of  the  guns  required  it  is  proposed  shall 
be  Eodman  12-inch  rifles,  notwithstanding  all  of  that  class  of  guns  here- 
tofore procured  for  the  army  or  navy  and  subjected  to  test  have  either 
burst  disastrously  before  the  lowest  reasonable  test  has  been  completed, 
or  have  given  such  indications  of  failing,  after  a  few  rounds,  as  to  be 
considered  unsafe.  It  is  proposed  also  to  purchase  610  10-inch  Eodman 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  7 

rifles,  although  the  committee  cannot  learn  that  any  gun  of  this  class 
has  ever  been  subjected  to  test  in  this  country,  except  the  Parrott  rifles 
of  that  calibre,  which  are  acknowledged  failures,  having  been  condemned 
by  botji  branches  of  the  service. 

No  progress  towards  obtaining  better  guns  is  likely  to  be  made  while 
the  ordnance  bureaus  are  organized  as  at  present ;  and  the  committee 
deem  the  best  way  to  secure  such  impartially  conducted  experiments 
as  will  determine  with  certainty  what  are  the  best  arms,  and  to  insure 
greater  economy  and  regard  for  the  public  interests  in  their  purchase 
and  adoption^  is  in  the  formation  of  a  mixed  ordnance  commission 
composed  of  officers  of  high  character  detailed  from  both  the  army  and 
navy,  who  shall  have  no  interest  in  patents  on  devices  for  arms.  The 
committee  report  the  accompanying  bill,  based  upon  the  conclusions 
before  set  forth  herein,  and  recommend  its  passage. 


APPENDIX  A. 

Testimony. 

WASHINGTON,  D.  C.,  November  7,  1867. 
HORATIO  AMES  sworn  and  examined. 

By  the  CHAIRMAN  pro  tern.  : 

1.  Question.  What  is  your  residence  and  occupation,  and  have  you 
had  any  experience  in  the  manufacture  of  heavy  guns  or  ordnance  ? 

Answer.  I  reside  in  Salisbury,  Connecticut,  and  my  occupation  is,  and 
has  been  for  the  last  30  years,  in  the  manufacture  of  wrought  iron. 

2.  Q.  Will  you  state  whether  you  have  had  any  contract  with  the 
Kavy  Department  for  the  manufacture  of  ordnance  j  and  if  so,  when  and 
of  what  calibre  and  description  such  guns  were  to  be ;  and,  generally, 
what  were  the  terms  of  the  contract,  stating  also  whether  you  have 
delivered  the  guns  or  they  have  been  accepted  from  you ;  and  if  not, 
why  they  have  not  been  so  delivered  or  accepted,  and  where  they  are 
now ;  and  give  a  general  history  of  the  whole  transaction  ? 

A.  In  the  summer  of  1861 1  conceived  the  idea  of  making  a  wrought- 
iron  rifled  cannon,  and  applied  to  the  Navy  Department  for  a  contract, 
and  received  an  order  to  make  five  50-pounders.  These  guns  were  made 
at  great  loss  to  me,  it  being  an  experiment.  One  of  the  guns  was  fired 
1,630  times  without  essential  injury.  Another  of  the  lot  was  made  into 
an  80-pounder  by  enlarging  the  bore  from  five  and  one-tenth  inches  to  six 
inches,  and  fired  480  times  without  damage.  Six  of  these  guns  were 
received  and  paid  for.  In  the  fall  of  1803  President  Lincoln  gave  me 
an  order  for  15  rifled  guns  of  the  largest  calibre  I  would  undertake  to 
make,  leaving  the  size,  shape,  and  calibre  to  me.  These  guns  were  com- 
pleted in  about  a  year  and  a  half.  One  of  them  was  fired  700  times 
with  more  and  heavier  charges  than  any  gun  has  been  knoAvn  to  stand, 
as  the  report  of  General  Gillmore,  Colonel  T.  T.  S.  Laidley,  and  Commo- 
dore Hunt  will  show.  Two  of  these  15  guns  came  apart  in  proof.  These 
guns  weighed  over  19,01)0  pounds  each,  and  our  machinery,  tools,  &c., 
were  not  large  enough  to  manage  the  work  successfully.  In  the  winter 
of  1865  I  received  another  contract  from  the  Navy  Department,  or  an 
order,  to  make  11  guns,  corresponding  to  the  one  proved  at  Bridgeport. 
These  gnus  were  made,  and  in  August,  1865,  one  was  ready  for  proof. 
The  government  reserved  to  itself  the  manner  of  rifling  the  guns.'  Two 
of  these  guns  were  rifled  in  different  methods,  by  order  of  the  depart- 
ment, of  untried  or  experimental  kinds ;  and  although  the  guns  were 
never  tried,  to  know  if  the  rifling  was  good  or  bad,  they  were  abandoned 
and  new  rifling  was  put  into  two  more  guns  of  60-feet  twist,  which 
insured  their  destruction,  as  there  was  not  twist  enough  in  them  to  give 
the  shot  the  proper  rotary  motion.  Four  of  these  guns  were  merely 
fired  to  burst  or  otherwise  destroy  them.  Each  was  merely  fired  into  a 
bank  of  earth  without  reference  to  precision,  range,  or  velocity.  The 
fifteenth  gun,  at  my  request,  was  fired  for  range,  at  Bridgeport,  and  it 
was  judged  that  the  twist  was  too  slow  to  do  good  work.  Besides,  the 
powder  which  was  ordered,  and  believed  to  be  1,450  feet  velocity,  gave. 


10  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

when  proved,  but  1,100  to  1,200  feet.  In  fact,  nothing  of  their  quality 
has  been  established  except  that  they  cannot  be  burst.  The  complaint 
that  the  bore  has  been  enlarged  by  tiring,  which  is  not  a  very  serious 
one,  can  be  remedied  by  firing  the  gun  with  heavy  charges  when  one- 
tenth  inch  below  size,  and  will  so  compress  the  metal  that  it  may  be 
fired  a  thousand  times  with  heavy  charges,  and  not  materially  further 
enlarge.  The  cracks  spoken  of  in  the  report  are  mere  fissures,  which 
are  not  dangerous,  and  have  not  so  proved.  All  wrought  iron  is  liable 
to  show  slight  fissures,  which  do  not  impair  its  value,  None  have  burst 
in  consequence  of  these  fissures,  and  they  can  scarcely  be  called  imper- 
fections. In  comparison  with  wrought-iron  guns  made  in  this  country 
and  in  Europe,  they  would  be  considered  perfect.  At  any  rate,  they 
have  stood  double  the  ammunition  at  the  charge  any  gun  we  have  has 
endured.  Were  you  to  examine  these  guns  now  you  would  have  no  hes- 
itation in  pronouncing  them  good  in  all  respects — conforming  to  the  con- 
tract. The  contract  for  these  guns  states  explicitly  that  the  normal 
charge  for  them  shall  be  10  pounds  or  12  pounds.  Yet  none  of  them 
have  been  fired  with  these  charges  to  show  their  endurance.  It  is  known 
that  the  istrain  upon  a  rifled  gun  is  twice  and  a  half  that  upon  a  smooth- 
bore gun,  and  that  40,000  pounds  pressure  upon  the  square  inch  of  the 
bore  is  the  standard  strain  of  common  powder.  Yet  my  gun  has  had 
used  in  it  powder  more  than  twice  as  strong,  which  I  believe  has  four 
times  the  tendency  to  burst  the  gun.  English  powder  gives  even  less 
than  40,000  pounds  to  the  inch.  These  100-pounder  guns  have  been 
made  of  the  kind  of  material  called  for  by  the  contract,  and  are  better 
guns  than  the  one  which  the  contract  specifies  they  shall  be  like.  A 
commission  was  .called  to  examine  these  guns,  on  the  question  whether 
these  "  were  suitable  and  proper  guns  to  be  put  on  board  ship."  They 
decided  they  were  not,  because  they  had  been  fired  with  excessive 
charges,  greater  than  they  would  ever  be  called  upon  to  bear.  The 
department  had  already  decided  the  question,  "that  no  gun  should  be 
put  on  board  ship  that  had  been  fired  to  excessive  proof."  This  commis- 
sion also  recommended  that  they  be  further  fired  with  the  charges  named 
in  the  contract ;  but  no  notice  was  ever  taken  of  this  recommendation. 
I  asked  the  bureau  to  make  a  comparative  test  with  any  gun  made  or  to 
be  made ;  but  it  was  refused.  With  the  charges  used  in  my  gun  almost 
every  shot  broke  in  the  firing ;  and  there  are  tons  of  shot  broken  in  the 
guns  and  out  of  them,  weighing  from  one  to  ten  and  twenty  pounds. 
And  I  venture  to  say  that  the  guns  rejected  by  the  department  will 
stand  with  equal  charges  rounds  enough  to  burst  100  guns  of  any  other 
make  the  government  possessed  of  equal  calibre.  These  guns  now  lie 
in  my  works,  six  of  them  finished,  and  five  of  them  wanting  the  rifling 
put  into  them  to  complete  them.  None  of  them  have  been  accepted.  I 
refer  you  to  the  evidence  given  before  the  Committee  on  the  Conduct  of 
the  War,  in  1864-'65,  and  the  testimony  given  by  Commodore  Hitchcock 
and  Commodore  T.  A.  Hunt,  on  the  proof  of  these  guns.  No  metal  can 
stand  the  strain  and  shock  of  powder  in  excessive  quantity  without 
injury;  and  my  meaning  of  the  contract  was  that  the  ordinary  powder 
used  (if  20  pounds  to  the  charge)  would  not  burst  the  guns,  and  it  has 
not.  And  I  do  not  believe  there  has  ever  been  a  gun  that  has  stood  so 
much.  I  am  informed  and  believe  that  a  wrought-iron  gun,  made  by 
direction  of  the  Navy  Department,  by  Captain  Ericsson,  at  a  cost  of 
from  $30,000  to  $40,000,  though  it  failed  completely  after  30  rounds,  was 
paid  for  in  full ;  also  an  80-pounder  wrought-iron  gun  made  at  Heading, 
Pennsylvania,  though  never  fired,  and  worthless,  was  paid  for  by  the 
department.  A  wrought-iron  80-pounder  was  made  at  the  navy  yard. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  11 

at  a  great  cost,  never  has  been  fired,  and  snows  unmistakable  evidence 
of  its  unfitness  for  service.  I  have  at  times  called  upon  the  department 
to  continue  the  firing  of  these  guns  with  suitable  powder  and  shot,  but 
my  request  has  not  been  complied  with ;  and  I  am  refused  payment  for 
my  guns  under  the  frivolous  pretext  that  they  do  not  answer  the  terms 
of  the  contract.  Had  these  guns  been  properly  rifled  and  proved  with 
their  normal  charges,  as  specified  in  the  contract,  no  complaint  could 
have  been  made  of  their  quality.  Nor  do  they  now  show,  after  the 
unparalleled  proof  they  have  withstood,  any  serious  fault. 


WASHINGTON,  November  11, 1867. 
THOMAS  TAYLOR  sworn  and  examined. 
By  Mr.  LOGAN: 

1.  Question.  I  understand  from  your  former  testimony  that  you  have 
had  considerable  experience  in  experimental  firing  of  guns  at  Fortress 
Monroe! 

Answer.  Yes,  sir. 

2.  Q.  Have  you  any  knowledge  of  the  bursting  of  any  Kodrnan  guns 
at  that  place  I 

A.  Yes,  sir. 

3.  Q.  Of  what  calibre  were  they  ! 

A.  Two  8-inch  burst  and  one  12-inch. 

4.  Q.  How  many  rounds  had  the  8-inch  guns  been  fired  respectively? 
A.  One  of  1,500  rounds  and  the  other  50.    The  12-inch  about  35. 

5.  Q.  Were  uniform  intervals  allowed  to  elapse  between  each  round  I 
A.  No,  sir;  we  fired  them  as  fast  as  we  could  load  and  fire  and  prepare 

instruments  to  take  velocities. 

6.  Q.  About  how  great  a  length  of  time  on  the  average  elapsed  between 
each  round  ? 

A.  Perhaps  ten  minutes ;  sometimes  it  might  be  half  an  hour. 

7.  Q.  Sometimes  longer  ? 

A.  Yes,  sir;  that  arises  from  the  machine  sometimes  not  working 
well. 

8.  Q.  After  each  round  you  applied  certain  instruments  and  made  a 
certain  examination  of  the  gun  I 

A.  No,  sir;  we  have  two  instruments  for  taking  the  initial  velocities; 
one  is  Schultz's  chroinoscope  and  the  other  Benton's  ballistic  pendulum. 
With  these  we  take  the  velocities.  They  sometimes  get  out  of  order. 

9.  Q.  What  was  the  weight  of  powder  used  in  the  8-inch  and  12-inch 
guns  respectively. 

A.  Fifteen  pounds  of  rebel  powder ;  which  gives  a  velocity  of  about 
1,250  feet  per  second. 

10.  Q.  Do  you  mean  to  say  rebel  powder  is  better  than  ours  f 

A.  We  had  some  powder  called  rebel  (which  I  suspect  was  English) 
which  was  very  good. 

11.  Q.  I  understand  you  to  say  a  12-inch  gun  burst  after  how  many 
rounds  ? 

A.  One  12-inch  burst  after  35  rounds.  That  is  known  as  the  Atwater 
navy  gun.  It  is  a  Rodman  gun  rifled  on  the  Atwater  principle. 

12.  Q.  How  long  a  time  was  consumed  in  firing  those  35  rounds  I 
A.  A  good  many  months — maybe  six. 

13.  Q.  Are  you  aware  of  any  other  12-inch  guns  that  have  been  made 
for  the  army  and  navy  ? 

A.  I  understand  there  are  two  others  made  for  the  navy. 


12  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

14.  Q.  Do  you  know  of  any  other  instances  where  they  have  burst? 
A.  These  burst.    There  were  but  three  of  them  made  and  they  burst. 

15.  Q.  How  many  rounds  were  these  others  fired  that  burst? 
A.  I  believe  they  all  burst  under  50  rounds. 

16.  Q.  What  kind  of  projectiles  were  fired  in  them? 

A.  The  projectiles,  I  believe,  were  mixed.  Parrott  projectiles,  I  think, 
were  mostly  used,  but  I  am  not  very  sure.  With  regard  to  the  two  that 
were  burst  by  the  Navy  Department,  I  have  only  second-hand  informa- 
tion. The  one  that  burst  at  Fortress  Monroe  was  served  mostly  with 
the  Dyer  projectile. 

17.  Q.  Will  you  explain  in  what  the  Atwater  system  of  rifling  consists? 
What  its  peculiarity  ? 

A.  It  consists  in  removing  one-half  the  lands  out  of  the  gun  from  the 
muzzle  towards  the  breach — one-half  in  number  and  one-half  in  length. 

18.  Q.  And  the  Dyer  projectile  extends  into  the  grooves  ? 
A.  Yes,  sir. 

19.  Q.  In  those  that  were  recovered  was  it  found  that  the  soft  metal 
band  had  expanded,  enlarged  in  the  grooves  towards  the  muzzle? 

A.  No,  sir. 

20.  Q.  What  kind  of  powder  did  you  use  ? 
A.  Generally,  I  believe,  mammoth  powder. 

21.  Q.  The  object  of  using  mammoth  powder  as  I  am  informed  is  to 
continue  the  pressure  of  the  gases  against  the  shot  farther  towards  the 
muzzle  ? 

A.  Yes,  sir. 

22.  Q.  And  yet  the  pressure  was  not  sufficient  to  expand  the  lead  into 
the  grooves  when  the  shot  had  moved  half  the  length  of  the  gun  ? 

A.  No,  sir;  in  no  case. 

23.  Q.  What  has  been  the  proof  of  heavy  guns,  as  far  as  you  know,  at 
Fortress  Monroe — that  is,  what  has  been  considered  the  proof  of  the 
guns  ? 

A.  We  were  firing  about  15  pounds,  which  was  the  standard  charge 
for  8-inch  guns. 

24.  Q.  How  many  rounds  firing  ? 
A.  Do  you  mean  at  a  time  ? 

25.  Q.  No,  I  mean  the  entire  proof. 

A.  We  did  not  prove  in  that  way.  Parrott  would  fire  ten  rounds  and 
be  done  with  it,  whereas  we  would  fire  a  thousand  if  it  would  stand  it. 

26.  Q.  Has  a  12  or  15-inch  gun  ever  to  your  knowledge  been  fired  20 
or  30  rounds  in  course  of  proof  in  as  rapid  succession  as  it  could  be 
loaded  and  fired  ? 

A.  Do  you  mean  rifled  ? 

27.  Q.  Yes,  I  mean  rifled. 

A.  A  rifled  12-inch  gun  has  been  fired  in  my  presence  10  times  with 
double  charges  in  35J  minutes. 

28.  Q.  Has  it  ever  been  fired  20  or  30  times  in  as  rapid  succession  ? 
A.  No,  sir. 

29.  Q.  Has  the  15-inch  Eodman  gun,  to  your  'knowledge,  ever  been 
fired  that  number  of  times  in  rapid  succession  ? 

A.  It  has  been  fired  10  times  with  hundred-pound  charges  in  my 
presence,  and  I  think  that  is  the  most  rapid  that  it  has  been  fired. 

30.  Q.  Do  you  know  any  reason  why  the  firing  was  not  continued 
beyond  the  10  rounds  as  a  further  test? 

A.  I  asked  the  colonel  if  it  would  not  be  well  to  fire  it  20  rounds  and 
get  over  the  assertion  of  Mr.  Wiard  that  it  could  not ;  and  he  did  not 
give  me  any  answer. 


EXPEEIMENTS  ON  HEAVY  ORDNANCE.  13 

WASHINGTON,  November  11, 1867. 

TIMOTHY  A.  HUNT,  commodore  United  States  navy,  sworn  and  ex- 
amined. 

By  the  OH  AIRMAN  pro  tern.  : 

1.  Q.  How  have  you  been  em  ployed  for  the  most  part  during  the  war? 
A.  In  the  fore  part  of  the  war  I  was  in  the  Pacific  ocean.    Was  ordered 

home  in  1862,  placed  on  ordnance  duty,  and  have  been  on  that  duty  since. 

2.  Q.  Were  you  a  member  of  the  commission  to  try  the  Ames  gun  at 
Bridgeport  in  1864  and  in  1866? 

A.  Yes,  sir. 

3.  Q.  How  many  did  you  try  in  1864  and  how  many  in  1866  ? 

A.  At  Bridgeport  we  tried  one  in  1866  for  range  only,  and  tried  two 
of  the  same  class  at  Falls  Village  in  the  same  year. 

4.  Q.  Will  you  state  what  was  the  result  of  those  trials  ? 

A.  The  first  gun  fired  in  1864  was  a  7-inch  bore.  It  was  fired  700 
rounds  with  different  charges  of  powder  from  19  pounds  up  to  30  pounds. 
It  stood  the  test  very  well. 

5.  Q.  In  making  a  trial  of  guns  do  you  use  a  charge  large  enough  to 
give  the  greatest  velocity  to  the  shot  ? 

A.  No,  sir;  in  proving  cast-iron  guns  we  use  the  service  charge  only, 
which  does  not  give  the  greatest  velocity — 10  rounds  of  the  service 
charge.  The  first  gun  is  fired  a  thousand  rounds  service  charge,  and  all 
after  that  is  made  as  near  like  the  trial  gun  as  possible,  and  fired  with 
10  rounds. 

6.  Q.  When  you  fixed  the  Ames  wrought-iron  gun,  did  you  use  the 
service  charge  ? 

A.  No,  sir ;  I  do  not  know  that  any  service  charge  had  been  determined 
upon  for  this  gun.  We  used  15  pounds,  25  pounds,  and  up  to  30  pounds 
of  powder.  Then  we  were  trying  the  strength  of  the  gun. 

7.  Q.  Did  you  make  any  calculation  to  ascertain  what  should  properly 
be  the  service  charge  for  a  gun  of  that  description  and  confine  your- 
selves to  that  ? 

A.  No,  sir. 

8.  Q.  Why  did  you  use  these  different  charges  I 

A.  To  see  what  the  gun  would  stand  and  how  far  it  would  throw 
shot. 

9..  Q.  Were  those  sized  charges  selected  by  the  commission  themselves 
or  were  they  used  under  instructions  from  the  Ordnance  Bureau?- 

A.  The  first  was  selected  by  the  commission ;  General  Gillrnore  was 
at  the  head  of  that. 

10.  Q.  Did  you  use  the  same  sort  of  charges  when  the  first  gun  was 
tried  I 

A.  That  was  the  one  I  have  reference  to,  in  which  we  used  charges 
of  25  pounds  and  30  pounds. 

11.  Q.  How  was  it  in  1866  I 

A.  That  gun  was  fired  merely  for  the  range. 

12.  Q.  With  large  charges  such  as  you  used  in  the  Ames  gun,  how 
many  rounds  could  you  fire  in  a  cast-iron  gun  without  destroying  it  ? 

A.  I  do  not  know,  sir ;  it  would  not  stand  so  many,  I  think,  as  the 
Ames  gun. 

13.  Q.  Would  it  stand  such  charges  at  all  ? 
A.  It  might  stand  a  few. 

14.  Q.  Did  you  make  reports  on  this  subject  to  the  Ordnance  Bureau 
from  Falls  Village,  Connecticut,  on  the  22d  day  of  February,  1866,  and 


14  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

from  the  same  place  on  the  10th  of  March,  1866,  and  on  the  14th  of 
March,  1866,  and  on  the  24th  and  27th  of  March,  the  10th  of  April,  and 
on  the  14th  of  September,  1866  ! 
A.  Yes,  sir ;  those  are  all  my  reports. 

15.  Q.  Besides  these  official  reports  made  by  you,  have  you  written 
any  unofficial  communications  to  the  chief  of  that  bureau  upon  the  sub- 
ject of  these  guns  f 

A.  Yes,  sir ;  I  made  some,  but  of  the  same  tenor  as  the  official  reports  ; 
and  those  private  reports  I  find  are  also  on  file. 

16.  Q.  Do  you  remember  to  have  said  anything  about  the  quality  of  these 
guns  more  fully  in  your  private  communications  than  in  the  official 
report  I 

A.  No,  sir ;  I  do  not  know  that  I  did. 

17.  Q.  What  was  the  kind  of  powder  used  in  your  proof  of  these 
guns? 

A.  I  think  the  powder  we  used  at  Bridgeport  was  No.  7  Hazard's 
powder,  with  initial  velocity  1,440  or  1,450  feet. 

18.  Q.  Was  it  a  quick-burning,  fulminate  powder,  more  likely  to  burst 
a  gun  than  that  ordinarily  used  in  the  service  charge  ? 

A.  No,  sir  j  I  think  not.  It  was  such  powder  as  we  put  on  ship-board. 
It  was  sent  from  New  York  magazine,  from  the  same  lot  out  of  which 
we  got  powder  to  put  on  ship -board  for  service. 

19.  Q.  Did  the  shot  break  in  the  gun  or  outside  of  it  in  these  trials  ? 
A.  Not  in  the  trial  at  Bridgeport.    I  fired  two  guns  afterwards  at 

Falls  Village.  We  fired  it  220  rounds  with  20  pounds  each  charge,  and 
shot  weighing  100  pounds,  and  five,  I  think,  of  10-pound  charges,  and 
10  of  15  pounds ;  making  235  charges. 

20.  Q.  With  what  result? 

A.  The  gun  was  very  much  enlarged  in  the  bore  in  the  rear  of  the 
shot.  Eight  in  the  centre  of  the  bottom  of  the  bore  there  was  a  depres- 
sion commenced  after  firing  15  or  20  rounds  ;  and  that  depression  kept 
eating  in  to  the  depth  of  four  inches. 

21.  Q.  How  large  was  that  orifice  in  circumference  I 
A.  Large  enough  to  insert  the  little  finger. 

22.  Q.  To  what  did  you  attribute  that  ? 

A.  The  pressure  of  the  powder ;  and  owing  to  the  sulphur  in  the  pow- 
der, when  any  abrasion  takes  place  in  cast-iron,  and  the  powder  once 
gets  hold  of  it,  it  eats  in  very  fast. 

23.  Q.  Then  it  is  not  to  be  accounted  for  entirely  by  the  pressure,  but 
by  the  corrosive  character  of  the  gases. 

A.  The  pressure  in  the  first  place  dents  it  in,  but  when  the  corrosive 
quality  of  the  gas  once  gets  hold  of  wrought  iron  it  eats  in  very  fast. 
There  were  some  other  defects  in  the  chamber  of  that  gun,  but  the  bore 
was  in  very  good  condition,  according  to  the  charge  of  powder. 

24.  Q.  What  was  your  general  conclusion  in  your  report  and  the  con- 
clusion you  arrived  at  in  your  mind  as  to  the  value  of  these  guns. 

A.  The  wrought-iron  guns  I  consider  the  strongest  guns  that  can  be 
made ;  stronger  than  any  we  have,  provided  the  welds  are  secure.  There 
is  no  doubt  that  gun  at  Bridgeport  stood  remarkably  well — longer  than 
any  cast-iron  gun  we  have  in  the  service.  I  think  the  last  two  guns 
that  I  fired  also  stood  charges  of  powder  that  cast-iron  guns  would  not 
stand. 

25.  Q.  How  would  it  have  been  in  active  service  if  these  guns  had 
been  used  with  a  proper  service  charge  j  do  you  consider  they  would 
have  been  effective  guns  I 

A.  I  do  not  think  they  would  have  enlarged  or  that  these  depressions 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  15 

would  have  occurred,  if  they  had  been  fired  with  less  charges.  I  think 
this  6T4Q~inch  gun  will  not  stand  successive  charges  of  20  pounds  of  pow- 
der and  100-pound  shot. 

26.  Q.  Is  it  your  opinion,  then,  that  if  these  guns  of  Mr.  Ames  had 
been  used  in  active  service  with  a  proportionate  service  charge  of  pow- 
der only,  they  would  have  proved  effective  and  useful  guns  I 

A.  It  is  very  probable,  sir. 

27.  Q.  Is  it  the  practice,  or  has  it  been  for  many  years,  of  the  Navy 
Department  to  test  guns  with  more  than  the  service  charge  ? 

A.  No,  sir;  I  have  proved  a  great  many  guns,  and  have  always  proved 
them  with  the  service  charge.  After  the  guns  are  offered  for  proof  we 
fire  them  with  10  rounds  service  charge. 

28.  Q.  The  reason  then  for  increasing  the  charge  in  the  trial  of  these 
guns  was  because  it  was  a  gun  of  new  manufacture  I 

A.  Yes,  sir ;  something  new ;  some  doubt  as  to  the  weld  of  the  gun. 

29.  Q.  And  it  was  not  the  ordinary  trial  of  a  navy  gun  ! 
A.  No,  sir ;  something  new. 

30.  Q.  Did  you  answer  in  regard  to  the  breaking  of  shot  f 

A.  No  shot  were  broken  in  the  gun  j  but  the  bands  would  fly  off  after 
leaving  the  gun,  but  the  most  of  them  broke  on  striking  the  bank  into 
which  they  were  fired. 

31.  Q.  Were  those  shells  with  soft  metal  bands  at  the  base  of  the 
shell ! 

A.  Yes,  sir;  composition. 

32.  Q.  Have  you  ever  known  what,  in  your  opinion,  was  a  better  or 
stronger  gun  in  our  service  than  this  Ames  gun,  as  you  would  judge 
from  that  trial  of  them  f 

A.  I  have  never  known  any  gun  to  stand  the  test  that  7-inch  gun 
stood,  and  also  the  one  that  was  fired  at  Falls  Tillage.  The  second  gun 
fired  at  Bridgeport  was  fired  only  45  times ;  that  was  not  much  of  a  test, 
it  was  merely  fired  so  as  to  get  the  range. 

33.  Q.  I  asked  if  you  know  of  any  better  or  stronger  gun  in  our  service. 
A.  I  say  the  first  gun  was  the  strongest  and  stood  the  best  test  of  any 

gun  I  have  known  in  our  service  ;  but  I  cannot  say  as  to  the  last,  for 
that  was  only  fired  45  times,  and  simply  to  secure  the  range. 

34.  Q.  Suppose  you  were  in  a  fight  with  an  enemy,  would  you  or  not 
like  to  trust  to  these  guns  such  as  you  tried  there  ? 

A.  It  is  a  new  gun,  and  there  is  some  doubt,  as  I  said  before,  about 
the  welding.  If  the  gun  is  perfectly  welded  there  is  no  stronger  gun 
made.  But  we  have  to  run  some  risk  with  all  guns,  cast  iron  as  well  as 
wrought  iron,  and  the  wrought  iron  being  a  new  gun  there  is  some  doubt 
about  it.  There  is  no  doubt  the  wrought-iron  gun  would  stand  remark- 
ably well  with  a  charge  of  10  pounds  or  12  pounds  of  powder. 

35.  Q.  If  you  can  get  a  good  gun  that  will  give  a  greater  velocity 
to  the  shot  than  any  other  having  more  strength  to  stand  the  charge,  is 
not  that  gun  proportionately  more  valuable  for  war  purposes  f 

A.  Certainly,  sir. 

36.  Q.  Will  any  cast-iron  rifled  gun  in  your  opinion  stand  the  shock 
of  a  charge  that  would  give  1,500  feet  velocity  per  second  ? 

A.  It  might  for  some  few  charges,  but  I  think  not  for  any  consecutive 
number  of  charges. 

Is  not  a  wrought-iron  gun  of  this  kind  strong  enough  to  give  that  or 
a  greater  velocity  if  you  can  depend  on  the  safety  of  the  gun  ? 

Yes,  sir;  I  think  that  these  guns  cannot  be  bursted  expansively.  If 
they  burst  anywhere  it  would  be  the  weld — fly  off  in  the  rear. 

Did  any  Ames  guns  out  of  those  you  proved  burst  f 


16  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

No,  Sir. 

What  defects  did  you  observe  developed  in  the  trial  of  the  gun  besides 
this  orifice  or  cavity  that  was  produced  at  the  bottom  of  the  bore  ? 

There  were  some  few  around  in  the  circle  of  the  bore.  A  crack  or 
cavity  went  nearly  round  the  gun,  and  that  kept  eating  in  as  we  fired. 

Was  it  at  a  line  where  the  weldiDg  took  place  I 

I  should  think  not ;  it  was  in  the  chamber  of  the  gun,  that  is  in  the 
bottom  of  the  bore. 

What  was  your  conclusion  in  regard  to  the  principle  upon  which  Mr. 
Ames  has  been  manufacturing  these  wrought-iron  guns  ? 

I  think  his  principle  is  the  best  we  know  of  at  the  present  day ;  think 
it  will  make  the  best  gun.  I  think  it  is  a  much  safer  way  than  welding 
them  in  coils  as  the  Armstrong  and  other  guns  are  made . 

37.  Q.  Do  you  know  how  that  process  is  accomplished  by  Mr.  Ames  ? 
A.  Yes,  sir;  there  are  three  rings — concentric  rings.    The  lower  one 

projects  a  little  and  the  next  one  a  little  more :  so  that  when  the  two 
parts  are  brought  together  to  be  welded,  these  rings  are  about  six  inches 
in  depth,  and  as  they  are  brought  together  the  middle  takes  first  as  the 
welding  goes  on,  and  the  outside  ring  takes  last,  with  the  object  of  let- 
ting off  the  scoriae  produced  by  the  oxidation  of  the  iron,  so  as  to  have 
a  clean  weld ;  and  if  you  can  keep  clear  of  all  these  cinders  and  the  ex- 
coriation which  takes  place  as  soon  as  the  iron  is  brought  to  the  atmos- 
phere, you  can  make  a  perfect  weld  of  it. 

38.  Q.  Was  your  attention  directed  to  the  rifling  of  these  guns  ? 

A.  The  rifling  of  the  guns  was  a  regular  twist — one  turn  to  60  feet. 
That  was  the  rifling  of  the  gun  which  I  fired  for  Mr.  Ames  at  Bridgeport, 
in  1865,  which  in  my  opinion  was  no  test  for  any  other  gun.  I  do  not 
think  there  is  any  comparison  to  be  made  with  that  and  any  other  gun. 
For  that  reason  I  fired  it  but  45  rounds. 

39.  Q.  That  twist  was  selected  and  ordered  by  the  Ordnance  Bureau? 
A.  Yes,  sir. 

40.  Q.  Do  you  know  whether  Mr.  Ames  himself  objected  to  that  rifling? 
A.  I  do  not  know,  sir.    When  I  saw  the  result  I  thought  it  bad  rifling 

to  give  long  range — that  there  was  not  rotary  motion  enough  for  the 
shot.  Before  the  force  of  the  shot  was  expended,  the  rotary  motion  was 
done  and  of  course  the  shot  would  not  go  as  far. 

41.  Q.  What  rifling  would  you  prefer  for  a  gun  of  large  calibre  like 
that — one  which  would  commence  with  a  slow  turn  and  quicken  as  it- 
approached  the  muzzle,  or  would  you  have  uniform  rifling  ? 

A.  There  is  a  difference  of  opinion  about  that. 

42.  Q.  I  know  there  is,  and  that  is  the  reason  why  I  ask  you  the  ques- 
tion. 

A.  We  know  very  little  about  the  rifling  of  guns.  My  idea  is  that  we 
should  get  a  number  of  guns  of  the  same  calibre,  and  rifle  them  all  dif- 
ferently, and  fire  them  with  the  same  powder  and  at  the  same  time,  and 
see  which  gives  the  greatest  range  and  velocity ;  and  that  until  that  is 
done  we  shall  reach  no  satisfactory  conclusion. 

43.  Q.  Do  you  know  whether  there  ever  has  been  such  an  experiment 
or  series  of  experiments  in  order  to  test  the  value  of  differently  propor- 
tioned rifling  of  guns,  by  either  the  army  or  navy  ? 

A.  There  were  some  experiments  made  by  the  navy  of  Parrott's  rifling, 
At  water's  rifling,  and,  I  think,  Rodman's  or  some  other,  and  it  was  con- 
sidered that  Atwater's  rifling  was  the  best,  gave  the  best  results. 

44.  Q.  What  is  the  peculiarity  of  that  rifling J? 

A.  It  is  that  after  the  shot  gets  started  he  cuts  away  the  grooves  so 
that  there  is  not  so  much  friction  half  way  down  the  gun.  The  lands 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  17 

were  cut  half  way  out  and  made  smaller  so  as  to  prevent  so  much  fric- 
tion and  cause  the  rotary  motion. 

45.  Q.  Do  you  know  whether  any  experiments  have  been  tried  with 
guns  precisely  similar  in  calibre,  length  and  construction  in  every  re- 
spect except  the  diiference  of  the  twist  in  rifling,  and  the  difference  in 
result  between  an  uniform  rifling  and  a  rifling  commencing  slowly  and 
increasing  ? 

A.  No,  sir  $  I  do  not  know  the  experiment  of  that  kind  that  has  been 
made.  They  may  theorize  as  much  as  they  please  about  gunpowder, 
they  never  can  come  to  any  conclusion  except  by  practical  tests. 

46.  Q.  Do  you  believe  the  velocity  of  shot  and  the  range  of  guns  can 
be  calculated  with  mathematical  accuracy,  when  you  have  the  calibre, 
the  weight  of  the  shot,  the  charge  of  powder  and  the  shape  of  the  shot 
all  given  ?    Or  do  you  think  it  is  necessary  to  add  experience  to  these 
conclusions  ? 

A.  There  must  be  experience  added  to  them.  If  everything  could  be 
made  exactly  alike,  they  might  do  it,  but  there  are  so  many  variations 
in  the  i>owder,  shot,  guns,  and  conditions,  that  it  cannot  be  carried  out 
to  a  mathematical  point. 

WASHINGTON,  November  11,  1867. 
E.  B.  HITCHCOCK  sworn  and  examined. 
By  the  CHAIRMAN  pro  tern  : 

1.  Question.  Will  you  state  in  what  service  you  are,  and  your  rank'? 
Answer.  I  am  commodore  in  the  United  States  navy. 

2.  Q.  What  is  the  ordinary  proof  to  which  smooth-bore  or  rifled  guns 
in  the  naval  service  are  subjected? 

A.  In  making  a  contract  or  engagement  for  any  special  class  of  guns 
they  take  the  first  of  that  class  and  submit  it  to  what  is  ternied  extra- 
ordinary proof,  that  is,  a  thousand  rounds  of  service  charge.  The  others 
are  supposed  to  be  duplicates  of  that  gun.  They  are  submitted  to  10 
charges  of  service  rounds. 

3.  Q.  You  take  one  gun  of  a  class  ? 

A.  Yes.  For  instance,  if  you  were  going  to  make  9-inch  guns  you 
would  take  the  first  and  submit  that  to  the  extraordinary  proof  of  1,000 
rounds. 

4.  Q.  The  extreme  proof  is  1,000  rounds  f 

A.  That  is  the  initiatory  proof  of  a  class  of  guns.  The  others  are 
supposed  to  be  duplicates,  and  before  reception  in  the  service  they  are 
fired  10  rounds. 

5.  Q.  What  is  the  extreme  proof  to  which  you  subject  such  guns  in 
the  navy,  as  it  regards  the  charge  of  powder  and  its  kind! 

A.  We  have  no  proof  for  powder  or  shot  in  the  ordnance  for  proving 
guns.  The  proof  of  powder  is  a  thing  by  itself. 

6.  Q.  But  what  is  the  extreme  proof  as  it  regards  the  size  of  the  charge? 
A.  That  depends  on  whether  it  is  a  smooth-bore  or  rifled  gun. 

7.  Q.  What  is  the  extreme  proof  to  which  you  subject  a  smooth-bore 
gun,  as  it  regards  the  size  of  the  charge  and  shot  used? 

A.  We  use  the  service  charge  all  the  way  through  for  any  kind  of 
proof  5  and  our  service  charges  for  smooth-bore  guns  have  varied,  gene- 
erally  to  one-fourth  and  one-eighth,  with  permission  to  use  one-third  in 
service  on  some  occasions.  During  this  last  war  there  were  special  pro- 
visions made  for  going  far  beyond  that.  It  was  restricted  at  the  com- 
mencement of  the  war  particularly  to  certain  charges.  Daring  the  war 
experiments  indicated  that  it  might  be  increased  with  safety,  and  per- 
mission was  given  to  increase. 
Eep.  No.  266 2 


18  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

8.  Q.  How  is  it  with  regard  to  rifled  guns? 
A.  One-tenth  is  the  service  charge. 

9.  Q.  Then  your  test  iu  the  navy  is  one  made  rather  by  the  number  of 
discharges? 

A.  The  durability  of  the  gun.  ^Looking  to  the  life  of  the  gun,"  as 
we  sometimes  call  it  in  service. 

10.  Q.  What  is  considered  the  measure  of  the  life  of  a  gun  in  the  naval 
service. 

A.  About  800  discharges.  Not  but  what  it  will  stand  more  than  that, 
but  we  look  for  about  800.  The  Ordnance  Office  has  withdrawn  them 
at  500.  But  we  think  when  a  gun  has  been  fired  800  rounds  it  ought  to 
be  withdrawn. 

11.  Q.  Your  rule  is  generally  that  you  test  guns  by  the  number  of 
rounds  you  fire. 

A.  Yes,  sir. 

12.  Q.  You  fire  a  number  of  rounds  with  the  service  charge? 
A.  Yes,  sir. 

13.  Q.  And  if  the  first  gun  of  a  class  stands  a  thousand  rounds  you 
are  ready  to  accept  the  others  always  upon  the  ordinary  test  of  10  rounds'? 

A.  Yes ;  ten  rounds  always  ;  those  numbers  are  fixed. 

14.  Q.  What  is  the  lowest  tensile  strength  of  iron  permitted  to  be 
used  for  guns  in  the  navy,  and  does  it  differ  in  those  of  different  cali- 
bres? 

A.  The  tensile  strength  is  a  thing  that  was  at  one  time  insisted  upon 
with  great  uniformity  and  great  confidence.  We  thought  we  might  rely 
upon  it.  Afterwards  we  became  doubtful  whether  it  Avas  an  indication 
of  that  importance  we  had  supposed  it  to  be,  and  of  late  it  has  not  been 
insisted  upon ;  so  that  I  can  hardly  say.  It  has  been  named,  you  will 
find  in  reports,  when  a  contract  has  been  made,  that  there  has  been  a 
certain  tensile  strength;  and  afterwards  orders  have  been  given  where 
it  has  not  been  insisted  upon  from  doubts  arising  in  relation  to  its  being 
so  reliable  an  indicator  as  it  was  once  supposed  to  be.  When  Major 
Wade  made  his  experiments,  followed  up  by  Mr.  Mordecai,  we  supposed 
we  had  an  infallible  guide.  I  think  now  they  have  more  confidence  in 
it  in  the  army  than  we  have  in  the  navy.  We  tried  the  tensile  strength 
of  iron  at  all  the  navy  yards.  We  have  specimens  of  the  guns,  but  we 
do  not  think  it  so  infallible  a  test  as  we  formerly  did. 

15.  Q.  Do  you  recollect  what  was  the  rule  ordinarily  observed  in  the 
navy  in  relation  to  iron,  as  to  the  highest  and  lowest  degrees  of  tensile 
strength  ? — what  were  the  two  extremes  ? 

A.  I  do  not  recollect,  sir;  but  it  is  a  matter  of  record  in  any  of  the 
text- books,  either  army  or  navy. 

16.  Q.  Did  you  approve  two  of  these  wrought-iron  rifled  guns  that 
were  constructed  by  Mr.  Horatio  Ames  I 

A.  We  fired  them  under  orders,  but  not  with  a  view  of  experiment  at 
all.  Definite  orders  were  given  me,  which  I  carried  out.  I  had  no  voli- 
tion in  changing  anything  at  all.  It  was  not  an  experiment  that  I  was 
sent  there  to  use  judgment  upon,  but  simply  to  carry  out  orders.  My 
duties  were  prescribed. 

17.  Q.  Instead  of  your  being  detailed,  then,  to  experiment  and  report 
your  judgment  of  the  guns,  you  were  detailed  to  perform  a  specific  duty  ? 

A.  Yes,  sir ;  and  to  report  the  result  as  facts. 

18.  Q.  How  many  charges  did  you  fire,  and  what  was  the  weight  of 
powder  and  shot  ? 

A.  I  will  have  to  ask  your  indulgence  to  refer  to  the  written  report. 
There  is  .a  written  report  of  all  these  details.  In  .the  last  twenty  years 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  19 

sir,  these  things  are  so  much  mixed  up  in  my  mind  that  I  may  uninten- 
tionally make  a  wrong  statement. 

19.  Q..  In  the  reports  that  you  made  to  the  Ordnance  Bureau  of  the 
Navy  Department,  on  the  12th  day  of  August,  1865,  and  on  the  4th  day 
of  September  of  the  same  year,  from  the  West  Point  foundry,  in  relation 
to  your  trial  of  the  Ames  guns,  did  you  confine  yourself  to  just  that  trial 
which  you  had  been  ordered  to  make  without  exercising  any  discretion 
of  your  own  ? 

A.  Strictly  so  ;  the  orders  were  definite  and  strictly  complied  with. 

20.  Q.  Will  you  tell  me  whether  that  is  the  usual  number  and  amount 
of  charges  used  in  proving  guns  of  that  calibre. 

A.  I  should  say  no,  sir ;  so  far  as  my  experience  goes.  The  bureau 
gives  orders  for  a  trial.  If  they  do  not  prescribe  differently  it  would  be 
10  ordinary  service  charges.  They  did  not  assign  to  this  gun  what  the 
service  charge  should  be.  If  it  had  been  a  gun  that  had  been  in  the 
service,  it  would  have  had  its  charges  assigned.  We  would  simply  have 
been  ordered  to  prove  this  gun  and  to  use  these  charges.  « 

21.  Q.  If  you  had  been  directed  at  your  discretion  to  make  that  trial, 
would  you  not  in  the  first  place  have  made  the  trial  with  the  ordinary 
service  charge  ? 

A.  In  former  times,  when  we  proved  guns,  we  used  excessive  charges — 
some  two  or  three  rounds,  but  very  excessive.  We  put  in  a  number  of 
projectiles  in  the  guns — smooth-bore  guns.  When  I  was  first  detailed 
for  ordnance  duty,  that  was  the  practice.  I  was  very  much  opposed  to 
it,  although  it  is  twenty  years  ago  ;  and  in  long  conversations  with  Com- 
modore Warrington,  then  chief  of  the  bureau,  I  think  I  influenced  him 
to  change  the  order  and  use  the  service  charges.  If  I  were  going  to 
have  service  charges  of  two  or  three  different  weights  of  powder,  I  would 
always  commence  with  a  new  gun  on  the  lowest  charges. 

22.  Q.  If  the  trial  had  been  left  to  your  discretion,  you  would  have 
gone  on  testing  with  charges,  and  endeavoring,  in  a  new  gun,  different 
from  any  former  one,  to  ascertain  what  would  have  been  the  proper  ser- 
vice charge  to  be  settled  for  that  gun  ? 

A.  We  would  ascertain  what  would  be  the  proper  charge. 

23.  Q.  You  would  have  calculated  what  would  be  the  proper  service 
charge  for  that  gun  and  have  made  your  trial  from  that  f 

A.  Yes,  certainly ;  and  if  practical  experience  confirmed  the  theory, 
we  would  have  held  to  it. 

24.  Q.  The  trial  made  with  this  gun  was  made  with  excessive  charges 
rather  with  a  view  to  see  whether  you  could  burst  the  gun,  to  ascertain 
what  its  duration  would  be  ? 

A.  No,,  sir;  that  was  not  my  impression.  They  commenced  by  using 
10  pounds  charge  and  increased  it  to  15-  pounds  and  20  pounds  to  see 
what  the  effect  would  be,  not  to  rupture  the  gun  ;  to  see  what  the  effect 
would  be  on  wrought  iron  cooled  in  the  manner  that  was.  I  suppose 
they  wanted  so  see  what  the  effect  of  10  pounds  would  be,  and  then  in 
increasing  it  to  see  if  it  produced  any  other  effect  on  the  wrought  iron. 

25.  Q.  Beside  your  report  made  after  the  trial  in  each  case,  did  you 
write  any  unofficial  letters  to  the  bureau  advising  them  on  the  subject? 

A.  I  cannot  say  whether  I  did  or  did  not,  sir.  We  were  in  the  habit 
of  writing  unofficial  letters  to  the  bureau.  I  have  written  a  great  many 
unofficial  notes,  but  we  were  very  much  pressed  at  that  time  in  relation 
to  our  work,  and  I  should  be  disposed  to  say  I  did  not.  But  I  cannot 
say  I  did  or  did  not.  I  have  no  recollection  of  doing  it. 

26.  Q.  Do  you  know  of  any  shot  that  were  broken  in  or  out  of  the  gun 
in  this  firing  ? 


20  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  I  do  fiot  remember  any  of  them  being  broken  there.  I  would 
rather  rely  upon  the  report  in  regard  to  that.  I  do  not  think  any  of 
them  were  broken  there,  sir. 

27.  Q.  Did  you  use  the  same  powder  in  firing  these  guns  you  did  in 
firing  the  Parrott  guns  ? 

A.  With  one  exception  I  have  never  used  any  but  service  powder. 
The  powder  for  these  guns  was  ordered  from  New  York,  just  as  any  pow- 
der for  proof  is  ordered.  It  was  not  a  selection  of  powder. 

28.  Q.  In  these  trials  of  the  Ames  guns  at  West  Point  foundry,   you 
used  the  same  powder  as  you  used  in  other  trials  f 

A.  Yes,  sir ;  used  the  ordinary  service  powder. 

29.  Q.  It  was  not,  then,  a  quick-burning,  fulminate  powder? 

tA.  It  was  either  to  be  cannon  or  No.  7  powder,  and  the  initial  velocity 
was  to  be  1,500  feet  for  one  and  so  much  for  the  other.  Those  standards 
are  laid  down  in  the  ordnance  instructions. 

30.  Q.  Did  you  use  what  is  called  the  water-proof  of  guns  there  some- 
times*'? and  if  so  describe  how  you  apply  the  water. 

A.  It  is  a  hydraulic  pump  of  very  small  construction  capable  of  rais- 
ing a  weight  of  two  atmospheres,  merely  pressure  enough  to  force  the 
water  into  any  cavity  that  may  exist.  It  produces  no  strain. 

31.  Q.  Did  you  put  either  of  these  guns  through  that  water-proof? 
A.  Yes,  sir ;  I  did. 

32.  Q.  With  what  effect? 

A.  There  is  no  effect  produced  by  that  unless  there  is  some  little  cavity 
which  will  retain  the  moisture  longer  than  other  parts. 

33.  Q.  If  a  gun  is  remarkably  porous  $he  water  sometimes  conies 
through? 

A.  -I  have  seen  it  come  through  wrought-iron  guns. 

34.  Q.  Would  the  degree  of  pressure  to  which  you  submitted  one  or 
both  of  these  guns  in  that  water-proof  have  burst  a  cast-iron  gun  ? 

A.  No  $  it  is  only  two  atmosphere.  It  is  not  used  with  that  idea.  The 
object  is  simply  to  find  whether  there  are  any  little  cavities.  I  never 
have  used  this  pressure  of  two  atmospheres  with  an  idea  I  was  going  to 
develop  anything  further  than  letting  the  water  get  into  some  porous 
place.  We  are  not  at  liberty  to  increase  the  hydraulic  pressure.  We 
are  confined  to  two  atmospheres. 

35.  Q.  Did  you  ever  fire  any  charges  in  a  Parrott  gun  of  the  same 
calibre  as  large  as  the  largest  you  fired  in  this  Ames  gun  ? 

A.  Yes,  sir ;  but  I  was  confined  to  certain  instructions.  I  have  tried 
experiments  with  Parrottfs  guns,  but  not  under  orders  from  the  ordnance 
bureau.  They  were  experiments  being  tried  with  guns  where  the  navy 
had  nothing  to  do  with  it. 

36.  What  was  the  effect  of  the  20  pounds  charge  on  the  Parrott  gun? 
A.  There  was  no  injury  to  the  gun  in  that  instance. 

37.  Q.  What  is  the  service  charge  now  in  a  Parrott  100-pounder  ? 
A.  Ten  pounds. 

38.  Q.  Is  that  regarded  as  charge  enough  to  give  the  highest  velocity 
to  the  shot? 

A.  They  settled  on  the  ten  pounds  as  a  mean,  as  being  the  best  in  the 
long  run  both  for  wear  of  the  gun  and  for  safety  and  for  many  other  con- 
siderations. Certainly  a  higher  velocity  might  be  obtained  with  more 
powder. 

39.  Q.  Would  you  consider  that  gun  a  good  gun  that  would  not  stand 
charge  enough  to  give  the  highest  velocity  to  the  shot  ? 

A.  Yes,  sir ;  but  I  would  consider  the  gun  that  would  give  the  greatest 
velocity  the  better  gun. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  21 

40.  Q.  Would  you  considerthat  a  good  gun  that  would  not  stand  charge 
enough  to  give  the  highest  velocity  ? 

A.  Yes,  sir ;  I  would  consider  such  a  gun  a  good  serviceable  gun,  yet 
not  the  best ;  because  the  best  would  be  one  that  would  combine  all  the 
advantages. 

41.  Q.  Do  you  know  the  Dahlgreii  shell  gun  ? 

A.  I  know  it,  but  not  enough  to  give  answers  in  relation  to  it. 

42.  Q.  Do  you  know  whether  that  gun  will  stand  a  heavy  enough 
charge  of  powder  to  give  the  highest  velocity  to  the  shot? 

A.  Some  of  them  would  not.  I  think  there  is  a  great  difference  in 
those  guns.  I  think  the  50-pounder  was  a  very  good  gun,  and  all  the 
large  ones  perfectly  worthless,  because  they  would  not  stand. 

43.  Q.  Do  you  know  any  gun  that  will  stand  any  considerable  number 
of  rounds,  yet  giving  the  highest  velocity  to  the  shot  ? 

A.  I  do  not  believe  they  exist  anywhere,  sir.  1  do  not  believe  any 
such  gun  has  yet  been  produced.  Not  any  large  number  of  rounds.  I 
think  there  are  guns  that  will  afford  the  highest  velocity  powder  can 
give  for  a  few  rounds. 

44.  Q.  After  the  experience  at  Fort  Fisher,  was  the  service  charge  for 
the  100-pounder  Parrott  gun  reduced? 

A.  I  am  not  quite  positive  about  that;  I  wasoii  board,  too,  in  relation 
to  that  charge.  I  am  rather  under  the  impression  it  was,  and  I  think  I 
voted  against  .it.  That  is  a  matter  of  record. 

45.  Q.  Is  not  the  service  charge  of  the  Parrott  gun  now  eight  pounds  ? 
A.  I  think  it  is  reduced  down  to  eight  pounds. 

46.  Q.  You  have  been  inspecting  these  Parrott  guns  for  years,  have 
you  not? 

A.  Not  for  the  last  two  or  three  years.  I  was  employed  a  number  of 
years  inspecting  them.  I  inspected  the  first  guns  the  navy  ever  took 
and  the  last  they  took,  and  all  between,  with  exception  of  one  year's. 

47.  Q.  What  was  the  cause  of  some  of  the  Parrott  guns  being  bored 
out  of  centre  ? 

A.  From  not  duly  watching  the  machine.  It  is  somewhat  difficult 
after  a  gun  is  bored  to  determine  whether  the  bore  is  precisely  in  the 
centre,  and  the  demand  was  so  urgent  that  some  were  sent  out  without 
having  been  properly  tested. 

48.  Q.  You  attribute  the  fact  of  any  guns  having  gone  out  which,  from 
defect  of  machinery,  were  not  bored  perfectly  in  the  centre,  to  the  haste 
of  producing  guns  required  at  that  time  ? 

A.  I  think  that  was  the  reason. 

49.  Q.  Can  you  throw  a  shot  from  a  Parrott  100-pounder  as  far  with 
8  pounds  or  10  pounds  of  powder  as  you  could  with  15  or  20  pounds  f 

A.  Certainly  not,  sir. 

50.  Q.  Are  you  acquainted  with  the  English  wrought-iron  steel  gun — 
particularly  the  Armstrong  gun  ? 

A.  No,  sir ;  only  from  general  Information. 

51.  Q.  Do  you  know  the  quantity  of  powder  used  for  the  charge  of  the 
•  different  calibres  of  those  guns  ? 

A.  I  have  seen  it  stated,  sir,  from  time  to  time.  They  have  charged 
the  amount  of  powder  in  those  guns  repeatedly.  They  have  advanced 
and  receded.  The  first  guns  put  on  their  naval  ships  was  at  a  very  low 
rate.  They  then  increased  them,  and  again  reduced  them.  I  knew  of 
the  firing  of  the  first  Armstrong  gun  made  in  the  United  State — made 
by  Mr.  Parrott — made  for  the  Russian  government,  sir.  W^hen  it  was 
supposed  to  be  a  secret  in  England  the  Russian  government  obtained 
by  some  means  the  plan  of  the  Armstrong  gun  and  brought  it  to  Parrott 


22  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

and  lie  made  one  of  the  guns ;  and  strange  to  say,  the  best  of  ranges  that 
have  ever  been  obtained  by  Armstrong's  guns  were  obtained  by  the  one 
made  by  Parrott — accidental,  undoubtedly. 

52.  Q.   Has  there  not  been  some  understanding  that  an  American 
inventor,  even  before  Armstrong's  time,  produced  a  gun  of  that  kind 
and  exhibited  it  to  the  navy  bureau? 

A.  Do  you  mean  Professor  TreadwelPs  gun  ? 

53.  Q.  I  do  now  know  whose  it  was. 

A.  There  is  a  gun  a  great  deal  like  Armstrong's  gun,  but  the  name  of 
the  inventor  has  escaped  me.  I  fired  the  gun  for  him  here. 

54.  Q.  How  long  ago  was  that  ? 

A.  That  was  15  or  18  years  ago.  Chambers's  gun,  ihe  first  one  he  got 
up,  was  a  good  deal  like  the  Armstrong  gun. 

55.  Q.  That  was  before  the  Armstrong  invention  came  out? 

A.  Yes,  sir;  before  we  knew  anything  about  it.  The  guns  did  not 
look  alike,  but  the  principle  was  very  much  the  same. 

56.  Q.  For  what  purpose  did  you  use  an  SO-pound  shot  in  a  100-pounder 
gun? 

A.  The  shot  was  used  for  penetration,  sir ;  to  determine  its  power  of 
penetration. 

57.  Q.  Will  you  explain  the  common  twist  of  the  rifling  used  in  the 
Parrott  gun  ? 

A.  It  is  an  increasing  twist — begins  slowly  and  increases  in  curve 
towards  the  muzzle. 

58.  Q.  Do  you  think  that  is  the  best  twist  for  a  100-pounder? 

A.  It  depends  on  the  projectile  that  is  used,  how  the  projectile  takes 
the  twist.  I  think  it  is  the  best  one  with  the  projectile  that  is  caused  to 
take  the  groove  by  the  band. 

59.  Q.  What  is  the  twist  of  tl^e  Ames  gun? 

A.  Two  twists — one  of  Mr.  Parrottfs  and  one  of  what  we  call  Brooks's. 

60.  Q.  One  was  a  60-foot  twist? 
A.  That  was  the  Brooks. 

61.  Q.  A  very  slow  twist,  was  it  not? 
A.  Yes,  sir. 

62.  Q.  What  do  you  think  of  that  60-foot  twist? 

A.  I  do  not  like  it,  sir,  for  the  projectiles  we  use.  Do  not  think  you 
get  as  great  an  effect. 

63.  Q.  Do  you  get  as  long  a  range  ? 

A.  I  do  not  think  you  do.  I  think,  as  I  said  before,  thu  ^arrott  twist 
is  the  best  adapted  to  the  expansibility  of  the  ring. 

64.  Q.  Do  they  fire  larger  charges  in  the  Armstrong  or  English  wrought- 
iroii  guns  than  in  the  rifled  guns  we  have  in  this  country  ? 

A.  Of  my  own  knowledge  the  last  of  the  Armstrong  guns  they  had  at 
•sea  was  fired  first  with  one-tenth ;  they  then  came  down  to  one- twelfth, 
having,  in  their  experiments,  gone  to  very  high  charges. 

65.  Q.  Who  is  Brooks,  and  how  came  that  rifling? 

A.  He  once  belonged  to  our  navy.    I  am  sorry  to  say  the  last  I  heard 
of  him  he  was  fighting  against  us.    Mr.  Brooks  is  a  man  of  a  good  deal* 
of  cleverness.    He  got  his  first  reputation  from,  a  sounding  apparatus 
when  he  belonged  to  the  Coast  Survey.    I  do  not  fancy  his  rifling.    How- 
ever, that  is  a  matter  of  mere  opinion.    He  does. 

66.  Q.  What  are  the  velocity  and  range  of  a  Parrott  100-pounder  gun 
charged  with  eight  pounds  of  powder  ? 

A.  That  I  cannot  say,  sir.  They  have,  I  think,  about  1,200  feet  with 
10  pounds  of  powder. 

67.  Q.  Since  the  reduction  of  the  charge,  do  you  know  of  any  experi- 
ments to  determine  the  range? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  23 

A.  I  never  saw  an  8-pound  charge  fired  out  of  one  of  these  guns,  and 
I  have  seen  thousands  upon  thousands  of  the  others. 

68.  Q.  You  think  that  gun  should  and  would  stand  10  pounds! 

A.  I  ought  to  think  so,  sir,  when  I  have  seen  20,000  or  30,000  rounds 
fired  with  them.  I  simply  base  my  opinion  on  that. 

69.  Q.  What  is  your  estimate  of  the  difference  in  value  between  a  gun 
that  must  be  fired  with  eight  pounds  of  powder  and  one  that  would 
stand  firing  with  15  or  20  pounds. 

A.  It  would  be  just  in  an  inverse  ratio  to  this  amount.  The  gun  that 
would  stand  the  heaviest  charge  would  be  the  most  valuable.  Run  it 
down  to  the  gun  that  would  not  stand  powder  enough  to  throw  the  ball 
out,  and  its  value  would  be  represented  by  a  0. 

70.  Q.  Do  you  know  of  any  gun  that  has  yet  been  produced  stronger 
than  the  experiment  would  lead  you  to  think  this  Ames  gun  might  be 
in  use  ? 

A.  My  ideas  may  be  very  peculiar.  I  was  called  upon  to  look  at  Mr. 
Ames's  effort  when  he  first  commenced  his  first  gun.  I  was  delighted  to 
see  he  had  struck  out  on  what  I  thought  was  dangerous  business,  to  work 
wrought  iron,  and  hoped  every  success  might  attend  his  effort,  knowing 
perfectly  well  that  was  the  siJfongest  form  iron  could  be  presented  in  if 
true  iron  all  the  way  through.  The  only  difficulty  in  my  mind  was 
making  it  perfect.  I  doubted  if  he  was  able  to  make  a  gun  with  perfect 
certainty.  He  made  a  gun,  and,  as  Colonel  Laidley  has  just  testified, 
and  the  report  shows,  it  was  fired  at  Bridgeport,  and  endured  remark- 
ably ;  but  the  question  was,  with  the  intention  of  making*  the  next  gun 
identically  the  same,  whether  he  would  be  successful,  or  could  be  assured 
it  was  the  same.  They  tried  another  gun  and  found  it  was  not.  That 
was  just  my  fear  of  the  danger  of  working  wrought  iron.  You  might 
cut  open  ten  guns  in  succession,  every  one  being  perfect,  but  I  am  not 
certain  the  eleventh  would  be.  I  am  not  a  mechanic,  but  I  have  watched 
them  at  their  work  a  great  deal,  and  I  find  them  very  frequently  making 
mistakes  in  heavy  welds.  The  high  heat  certainly  oxidizes  iron  very 
frequently.  That  oxide  interposes  itself  between  the  true  iron.  I  think 
I  have  seen  that  in  one  of  Mr.  Ames's  guns. 

71.  Q.  Your  idea  then  is  this,  that  in  making  cast-iron  guns  there  may 
be  such  uniformity  in  the  character  of  the  material  employed  that  you 
can  safely  trust  to  a  class  of  guns  when  one  of  that  class  stands  the 
required  test  I 

A.  Yes,  sir. 

72.  Q.  But  in  the  case  of  wrought-iron  guns  you  could  obtain  satisfac- 
tion only  by  the  testing  of  each  particular  gun  ? 

A.  Yes,  sir.  I  think  in  the  present  art  of  working  iron  there  has  been 
greater  uniformity  with  cast  than  with  wrought  iron  in  large  masses. 
They  make  gun-barrels  of  wrought  iron  with  great  success.  The  time 
may  come  when  they  may  work  wrought  iron  with  like  success  in  large 
quantities 5  but  they  have  not  done  it  yet  in  France,  England,  or  the 
United  States,  that  I  have  seen.  Nobody  doubts  that  wrougfit  iron  is 
stronger  than  cast.  There  is  a  great  difference  in  the  effects  on  the 
metal  inside.  Cast  iron  is  less  injured  by  the  action  of  the  interior  of 
the  gun  than  any  metal  I  have  ever  seen ;  and  steel  one  of  the  most  easily 
injured. 

73.  Q.  Is  that  owing  more  to  the  concussion  or  pressure,  or  to  the  cor- 
roding effect  of  the  gases  produced  by  combustion  ? 

A.  I  think  it  is  the  absence  of  the  junction  of  true  iron.  Wrought 
iron  almost  always  assumes  a  laminar  form  $  arid  between  these  leaves, 
as  it  were,  a  foreign  substance  seems  to  interpose  which  the  gas  acts 


24  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

upon.  In  this  examination  of  Mr.  Ames's  guns  he  was  not  present,  being 
absent  in  Europe.  In  examining  the  interior  of  the  gun,  we  took  a  small 
piece  of  steel  and  bent  it  at  right  angles,  bringing  it  down  to  a  cutting 
point  less  than  ^-inch  in  width.  We  put  it  on  a  light  handle  and  drew 
it  through  the  grooves  of  the  gun.  This  would  find  a  little  resting  place, 
but  when  you  looked  at  it  it  looked  like  a  mirror.  We  could  see  that  it 
was  not  an  imperfect  weld  this  was  catching,  but  on  the  iron  itself  in  its 
laminar  form.  When  we  came  to  fire  it  this  became  very  apparent. 

74.  Q.  Was  this  observation  made  before  or  after  the  firing  I 

A.  Before  an.d  after  each  fire,  sir.  Impressions  were  taken  of  the 
whole  interior  of  that  gun,  and  I  presume  are  now  in  the  ordnance 
department. 

75.  Q.  Was  that  lamination  increased  much  by  the  firing  ? 

A.  O,  very  much,  sir  j  very  much.  I  have  seen  larger  defects  than 
that  in  a  cast-iron  gun,  and  the  gun  stand  1,400  or  1,500  rounds. 

76.  Q.  Have  you  come  to  the  conclusion  that  a  wrought-iron  gun  can- 
not be  made  of  large  calibre  perfect  enough  to  be  used  and  adopted 
safely  in  practice  I 

A.  I  think  you  can  make  the  strongest^un  we  know  out  of  wrought 
iron.  I  think  there  would  be  a  perfect  uncertainty  in  relation  to  the 
guns.  One  of  them  will  stand ;  another  will  not.  I  think  they  would 
be  afa dangerous  class  of  guns  until  they  know  more  than  I  think  they 
know  now. 

77.  Q.  How  do  you  account  for  the  bursting  of  those  Parrott  guns  at 
Charleston  and  Fort  Fisher  ? 

A.  I  think  it  occurred  from  various  causes,  sir.  You  never  can  make 
a  large  number  of  guns  out  of  any  material,  wrought  iron  or  cast  iron, 
but  you  will  have  some  guns  that  have  inherent  weakness.  Some  of 
those  guns  may  have  exploded  from  that  cause.  My  theory  has  been 
that  the  greatest  injury  came  from  the  projectiles. 

78.  Q.  You  attribute,  then,  the  bursting  of  so  many  of  those  guns 
rather  to  the  projectiles  that  were  used  ? 

A.  The  majority  of  them  were  found  to  have  the  projectile  burst  in 
them,  and,  of  the  remaining  part,  there  was  no  record  to  show  whether 
the  facts  were  the  same  or  not. 

79.  Q.  Was  not  that  the  difficulty  with  regard  to  a  great  proportion 
of  thos§  that  burst — a  want  of  data  ? 

A.  Thsre  was  a  very  great  want ;  but  in  a  great  many  instances  there 
was  information.  A  remarkable  thing  took  place  there.  An  officer, 
Captain  Temple,  came  up  to  West  Point  to  see  the  firing  that  was  going 
on,  and  pick  up  some  little  ideas  in  relation  to  ordnance.  I  tried  to 
impress  upon  him  that  there  was  a  great  necessity  of  using  grease — not 
to  lubricate  the  shell,  but  to  burn  grease  in  the  gun  at  every  discharge ; 
and  also  that  the  coating  of  the  shells  inside  should  be  strictly  attended 
to  to  prevent  premature  explosion  of  the  shell.  He  took  command  of  a 
vessel  and  went  down  there.  He  attended  to  both  my  suggestions,  and 
did  not  have  a  premature  explosion  of  a  single  shell;  was  the  only  vessel 
that  escaped  it";  nor  did  he  have  a  gun  injured. 

80.  Q.  What  was  his  vessel  ? 
A.  I  do  not  recollect  the  name. 

81.  Q.  Was  that  at  Fort  Fisher  or  Charleston? 

A.  Fort  Fisher.  I  can  state  another  thing:  in  firing  these  elongated 
projectiles,  where  there  is  a  great  deal  of  powder  in  the  interior  of  the 
shell,  I  fired  some  to  try  and  find  out  what  was  the  cause,  if  I  possibly 
could,  of  so  many  shells  bursting  prematurely.  I  plugged  up  the  shell 
and  fired  a  number  of  them  over  at  the  bank  across  the  Hudson.  I 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  25 

recovered  the  shell  and  cut  them  open.    The  powder  inside  was  caked  so 
hard  that,  in  cutting  through  it,  it  polished  like  a  piece  of  slate. 

82.  Q.  Did  you  ever  in  your  trial  of  guns  burst  a  gun  by  bursting  the 
projectile  in  the  gun  f 

A.  No,  sir ;  not  entirely  to  rupture  the  gun,  but  to  an  indentation  very 
deep,  and  only  wonderful  the  gun  should  not  have  yielded. 

83.  Q.  Do  you  believe  a  gun  could  be  injured  by  the  bursting  of  a  pro- 
jectile in  the  gun  without  deep  indentation  on  the  interior  surface  of  the 
bore  f 

A.  Yes,  sir ;  I  have  seen  a  gun  that  has  been  burst  where  the  whole 
bore  of  the  gun  has  been  swelled  outward,  and  there  was  strong  evidence 
that  the  gun  burst  from  its  obstruction. 

84.  Q.  Then  you  would,  in  every  case,  expect  deep  indentation,  or 
forcing  out  of  true  line  the  bore  of  the  gun,  if  a  projectile  exploded  in  the 
gun! 

A.  Not  necessarily.  The  most  natural  thing  would  be  that  the  gun 
would  be  spread  there,  yet  it  is  possible  to  take  place  and  not  do  it. 

85.  Q.  Is  there  any  prevailing  character  of  fracture  you  ever  discov- 
ered in  the  bursting  of  these  Parrott  guns,  whether  up  next  the  band 
or  at  the  muzzle  f 

A.  I  do  not  know  that  1  could  say  there  is  any  prevailing  character. 
My  observation  would  go  to  say  rather  that  they  had  yielded  from  the 
vent-hole.  The  first  crack  in  the  metal  comes  from  the  rear  of  the  vent 
as  a  general  thing. 

86.  Q.  Do  not  they  appear  to  have  fractured  in  all  kinds  of  ways  f 

A.  Yes,  sir.  The  first  indication  you  find  of  any  yielding  in  a  gun — I 
do  not  mean  where  you  explode  shells,  but  the  wearing  out  of  the  gun — 
is  the  crack  that  takes  place  there.  I  have  seen  that  in  hundreds  of 
instances. 

87.  Q.  What  you  mean  then  is,  that  in  long  use  of  a  gun  the  first  place 
at  which  there  is  indicated  a  giving  way  of  the  gun  is  generally  there  at 
the  vent  ? 

A.  It  is  across,  at  right  angles  to  the  bore ;  whereas  in  smooth-bore 
guns  the  line  of  the  first  fracture  is  forward  of  the  vent.  The  English 
and  French  say  the  same  in  relation  to  theirs. 

88.  Q.  Did  you  fire  a  50-potmder  gun,  made  of  semi-steel  by  Mr.  Wiard, 
up  to  extreme  proof  ? 

A.  I  fired  a  gun  that  Mr.  Wiard  had  made  as  a  contractor.  My 
impression  is  that  that  gun  was  not  fired  up  to  1,000  rounds,  but  between 
400  and  500,  sir;  near  500.  This  was  in  1861.  It  was  the  first  gun  of 
that  kind  fired  at  Staten  Island. 

89.  Q.  Did  you  find  that  gun  deteriorate  under  these  experiments  ? 
A.  It  stood  remarkably  well. 

90.  Q.  Did  you  afterwards  fire  other  guns  of  the  same  kind  a  less  num- 
ber of  rounds,  and  if  so,  with  what  result  *? 

A.  Yes,  sir ;  part  of  them  burst.  One  of  those  that  burst  had  a  false 
chamber  introduced  into  it.  It  was  on  that  account  that  objection  was 
raised  to  the  guns — I  raised  it  myself — that  there  was*  an  attempt  -to 
defraud  in  making  the  guns,  and  therefore  tlilre  was  nothing  produced 
by  the  makers  that  should  be  received  for  a  moment.  I  stated,  as  I  then 
believed,  that  Mr.  Wiard  knew  nothing  of  it ;  but  I  did  not  look  upon 
him  as  the  maker  of  the  gun ;  he  was  the  contractor  and  got  these  guns 
made. 

91.  Q.  This,  if  I  understand  you,  confirms  your  idea  that  in  the  case 
of  a  steel  or  wrought-irou  gun  there  is  no  safety  without  a  trial  of  each 
particular  gun.    Are  these  guns  that  were  fired  and  burst  at  ten  rounds 
similar  to  that  which  stood  the  480  rounds  ? 


26  EXPERIMENTS  ON  HEAVY  ORDNANCE, 

A.  Yes.  I  say  in  the  report  that  I  supposed  at  that  time  that  Mr. 
Wiard  had  no  knowledge  of  that  deception ;  that  only  exonerates  Mr. 
Wiard  as  a  contractor.  They  made  a  gun  that  had  too  long  a  bore. 
They  wanted  to  shorten  that,  and  inserted  a  piece  at  the  bottom  of  the 
bore.  This  gun  was  blown  up.  Mr.  Wiard  disclaimed  any  knowledge 
of  this  thing.  I  say  in  the  report,  "I  have  no  cause  to  think  Mr.  Wiard 
had  knowledge  of  this  transaction."  1  did  so  think  at  that  time ;  I  do 
not  think  so  now.  I  said  then,  "I  believe  Mr.  Wiard  to  have  acted  in 
good  faith  in  all  these  transactions"  about  those  guns,  but  I  have  changed 
my  mind  since,  from  reports  that  have  come  to  me  since.  He  says  he 
did  not  know  it  at  that  time,  and  I  do  not  charge  him  with  knowing  it  now. 
But  now  there  is  testimony  furnished  in  the  Ordnance  Office  that  clears 
up  this  point. 

92.  Q."  You  have  no  knowledge  since,  yourself,  on  the  subject  f 

A.  No,  sir,  nothing ;  only  reports  that  have  been  in  existence  since. 
This  establishment,  where  Mr.  Wiard  had  the  guns  made,  got  into  a  muss 
among  themselves,  and  have  charged  all  sorts  of  things  against  each 
other.  I  have  no  knowledge  of  the  credibility  of  the  witnesses.  My 
impression  is  that  one  of  the  reports  was  that  Mr.  Wiard  avoided  a  knowl- 
edge of  where  defects  were  in  the  guns ;  that  he  kept  himself  aloof  from 
knowing  it., 

93.  Q.  I  think  you  said  that  some  of  these  Wiard  guns  fired  with  five- 
pound  charges  burst  at  10  rounds. 

A.  Yes,  sir. 

94.  Q.  Did  those  that  burst  show  any  defects  either  in  the  welds  or  by 
exhibition  of  Iarnina3  ? 

A.  I  think  not,  sir;  still  I  would  rather  go  back  to  those  reports, 
because  I  might  do  injustice  from  want  of  recollection. 

95.  Q.   Were  they  of  the  same  size  and  calibre  of  the  Dahlgreu 
50-pounder  ? 

A.  Copies  of  them. 

96.  Q.  The  difference  being  they  were  of  steel. 

A.  My  impression  is  something  like  this.  The  finish  of  those  guns  was 
beautiful,  and  made  them  a  very  attractive  gun  to  the  eye.  Everything 
appeared  well  about  the  gun.  We  commenced  to  fire  with  the  intention 
of  going  up  to  1,000  rounds ;  it  was  dropped  short  of  that,  and  at  that 
time  I  thought  remarkably  well  of  the  gun ;  but  when  this  attempt  at 
deception  was  discovered,  the  whole  thing  was  dropped.  Never  was  any- 
thing done  about  it. 

97.  Q.  Was  it  the  first  gun  tried  that  you  fired  the  480  rounds  I 
A.  Yes,  sir ;  the  first  gun. 

98.  Q.  Were  the  other  guns  there  at  the  same  time  ? 

A.  I  could  not  say  whether  they  were  down  at  the  ground  or  up  at  the 
place  where  they  were  being  finished. 

99.  Q.  Who  selected  the  gun  to  be  tried  ? 

A.  I  think  it  was  the  first  gun  finished.  I  do  not  think  there  was  any 
selection  about  it.  I  have  no  remembrance  now  of  any  defects  being 
found  about  these  guns  that  would  cause  one  to  be  picked  out  as  inferior 
to  the  other.  There  havar  been  no  guns  presented  to  the  government 
that  presented  a  better  appearance  than  they  did. 

100.  Q.  You  say  of  those  steel  guns,  the  rest  of  which  were  fired  with 
10  rounds,  that  some  burst  and  some  did  not ;  do  you  recollect  how  many 
burst  and  how  many  stood  the  test  ? 

A.  I  could  not  say  how  many  were  fired.  I  have  a  sort  of  glimmering 
idea  that  two  burst. 

101.  Q.  How  do  you  account  for  the  bursting  of  the  Wiard  50-pouuder, 
which  seemed  to  be  perfect  in  its  structure  ? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  27 

A.  I  think  those  guns  were  made  out  of  different  material.  I  did  not 
think  so  at  the  time,  but  since  then  1  am  inclined  to  think  the  same  mate- 
rial was  not  used  for  making  all  the  guns. 

102.  Q.  You  think  the  guns  which  burst  were  npt  made  of  the  same 
material  as  the  ones  that  stood  the  test  ? 

A.  I  could  not  say  that,  sir,  because  the  thing  was  dropped  right  there, 
and  no  examination  was  carried  on  about  it.  But  there  is  a  report  in 
circulation  that  the  last  forgings  were  made  of  wrought  iron. 

103.  Q.  Was  it  your  theory  to  account  for  the  bursting  of  these  guns 
that  there  was  a  variety  of  material  put  into  the  gun  in  any  instance, 
which  burst,  or  whether  the  gun  burst  was  made  of  a  material  different 
from  that  which  stood  the  ordeal  ? 

A.  Not  at  that  time ;  because  I  supposed  everything  was  perfectly 
honest  and  straightforward  up  to  the  moment  we  found  the  guns  had 
been  tampered  with,  and  then  the  thing  was  dropped.  I  never  prose- 
cuted the  investigation,  but  since  then  this  idea  of  different  material  has 
been  suggested.  If  that  is  so  we  may  account  for  it. 

104.  Q.  To  reduce  the  length  of  the  bore,  then,  you  found  they  had 
filled  up  the  end  of  the  bore  next  the  breach  I 

A.  Yes,  sir;  therefore  the  true  thickness  of  the  breach  was  at  this 
point  less  than  it  should  be. 

105.  Q.  Was  that  done  in  the  case  of  the  one  that  stood  the  test ! 

A.  O,  no,  sir  ;  only  done  in  one  gun ;  no  probability  that  it  was  extended 
to  any  one  but  that. 

106.  Q.  Then  you  did  not  prosecute  the  trial  because  this  was  found  to  be 
the  case  with  one  of  these  guns? 

A.  Yes,  sir ;  that  is  an  old  established  usage — more  than  20  years  old — 
that  where  any  defect  in  a  gun  is  conceded  by  the  contractor,  it  vitiates 
the  whole  contract. 

107.  Q.  A  discovery  of  that  kind  might  properly  affect  the  validity  of 
the  contract,  or  the  acceptance  of  the  gun  from  that  contractor,  but 
would  not  bear  on  the  question  of  the  value  of  the  gun  which  stood  the 
trial  ? 

A.  Not  at  all. 

108.  Q.  What  is  the  objection  to  the  gun  that  did  not  stand  the  trial  ? 
A.  Nothing ;  only  it  fell  under  this  category  of  rejecting  everything 

that  came  from  makers  that  attempted  to  deceive  you.    But  whether  a 
good  gun  could  be  made  on  that  principle  is  not  brought  in  question. 

109.  Q.  State  whether  the  blocking  or  filling  up  the  rear  part  of  that 
bore  was  a  cause  of  weakening  the  gun  1 

A.  I  should  rather  incline  to  say  yes.  There  is  generally  given  in  the 
construction  of  all  guns,  as  in  everything  else,. a  little  excess  for  safety. 
Whether  this  gun  was  heavy  enough  at  the  breech  to  admit  of  the  loss 
of  two  inches  might  be  a  question.  I  could  not  tell  without  going  into 
a  minute  calculation. 

110.  Q.  What  depth  of  metal  would  you  think  required  in  a  gun  of 
that  character  in  order  to  give  sufficient  strength  to  the  breech  from  the 
bottom  of  the  bore  through  to  the  breech  of  the  gun  ? 

A.  I  should  think  a  less  amount  would  answer  than  was  in  that  gun. 
I  think  the  thickness  was  rather  excessive  in  the  design  of  that  gun. 

111.  Q.  Was  that  one  of  the  guns  that  burst  ? 
A.  Yes. 

112.  Q.  I  understand  that  these  guns  which  were  produced  by  this 
contractor  were  rejected,  the  whole  lot  of  them,  because  there  was  found 
in  one  of  them  which  burst,  an  addition  of  metal  at  the  rear  end  of  the 
bore,  put  there  for  the  purpose  of  reducing  the  length  of  the  bore  ? 


28  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  Yes,  sir ;  it  was  on  account  of  this  deception  that  the  guns  were 
thus  all  rejected. 

113.  Q.  Do  you  consider  that  as  touching  the  question  whether  a  gun 
of  that  kind  might  or  might  not  be  a  valuable  gun  ? 

A.  Not  at  all,  sir. 

114.  Q.  It  is  a  matter  which  affects  the  question  of  receiving  guns  from 
that  particular  contractor  ? 

A.  Yes,  sir. 

115.  Q.  How  do  you  account  for  the  bursting  of  the  Wiard  50-pouiider, 
which  showed  perfect  structure,  and  the  endurance  of  a  cast-iron  gun, 
made  of  metal  only  one-fourth  of  its  tensile  strength? 

A.  I  cannot  account  for  it,  because  that  subject  .was  never  exhausted. 
The  investigation  was  dropped,  and  I  never  recurred  to  it.  The  merit 
of  the  guns,  as  guns,  I  have  never  taken  up  from  that  day  to  this. 

116.  Q.  Then  this  trial,  in  your  opinion,  has  not  determined  the  merit 
of  these  guns  as  guns,  but  only  the  claim  of  the  contractor  as  a  contractor  f 

A.  That  is  all. 

117.  Q.  You  never  considered  your  trial  of  the  guns  as  completed,  in 
view  of  satisfying  yourselves  as  to  the  merits  of  the  gun  itself? 

A.  It  was  not,  sir ;  you  will  find  the  report  was  closed  abruptly  by  this 
occurrence.  A  final  decision  never  was  made  of  those  guns  as  guns. 

118.  Q.  You'  say  you  suppose  they  were  not  all  made  of  the  same 
material  I  * 

A.  I  have  supposed  so  since  that  report  was  written ;  since  the  disturb- 
ance referred  to  took  place. 

119.  Q.  But  you  have  no  knowledge  on  the  subject  f 
A.  None  at  all. 

120.  Q.  State  whether  Mr.  Wiard  was  present  at  the  trial ;  and  if  so, 
what  explanation  he  gave  of  the  bursting  of  the  guns J? 

A.  Mr.  Wird  has  given  me  so  many  theories  at  times  that  I  truly  do 
not  recollect  just  what  particular  theory  he  then  advanced.  I  do  recol- 
lect that  we  kept  talking  pretty  much  all  the  time  we  were  down  there. 

121.  Q.  Do  you  recollect  whether  he  did  or  did  not  explain  that  it  was, 
in  his  opinion,  owing  to  the  expansion  by  heating  the  gun? 

A.  Those  were  subjects,  generally,  of  constant  conversation  with  us 
both:  All  kinds  of  theories  were  discussed  there  by  us,  and  if  Mr.  Wiard 
says  he  told  me  that  at  the  time,  I  should  not  doubt  that  he  did,  but  I 
have  no  recollection  of  it ;  I  recollect  his  discussing  these  things. 

WASHINGTON,  November  11, 1867. 
STEPHEN  V.  BENET  sworn  and  examined. 
By  the  CHAIRMAN  pro  tern. 

1.  Question.  State  whether  you  are  in  the  United  States  army,  and 
your  rank  ? 

Answer.  I  am  a  major  of  ordnance  in  the  United  States  army,  and 
brevet  lieutenant  colonel. 

2.  Q.  Did  you  make  a  proof  of  the  powder  used  in  the  experiments 
with  Mr.  Ames's  gun  ? 

A.  Two  samples  of  powder  were  sent  me  from  New  York  recently,  by 
Colonel  Laidley,  with  the  request  that  I  should  get  the  initial  velocity 
and  pressure  on  the  bore.  Whether  I  learned  at  that  time  or  was  told 
afterwards  it  was  powder  that  had  been  used  with  the  Ames  gun  I  do 
not  remember;  but  I  believe  it  was  the  powder.  I  made  the  test  4?  that 
powder  in  the  usual  way  we  test  powder  there  for  the  service,  and  sent 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


29 


him  an  official  abstract  from  my  record.  Beyond  this  I  don't  know. 
The  following  is  the  official  record  of  the  test  that  I  made  with  those 
samples : 


«                               Powder 

Initial  velocity. 

Strain  on  gun. 

Date. 

g 

P 
§ 

1 

a 

5 

§M 

| 

1 

1 

r 

<w 

5 

. 

'S  S 

& 

£ 

o 

S 

O 

&.C 

£ 

| 

I 

£§, 

o 

. 

c 

5 

| 

1 

1 

S3  '" 

•5 

i 

i 

2 

.  5 

i 

a 

IS 

i 

1 

1 

1866. 
Aug.  10  . 

1.  7212 

Mixed,  from 

Little.  . 

Aug.     8 

18.3 

1360  9 

87  300 

No.    5    to 

mortar. 

Sept.  13 

1.  6504 

No.  7 

None 

Sftnt.   11 

21.8 

1142  4 

77  300 

20.5 

1214.  9 

79,  800 

WASHINGTON,  November  11, 1867. 
THEODORE  T.  S.  LAIDLEY  sworn  and  examined. 
By  the  CHAIRMAN  pro  tern : 

1.  Question.  State  whether  you  belong  to  the  army  of  the  United 
States,  and  if  so  to  what  arm  of  the  service,  and  what  is  your  rank? 

Answer.  I  belong  to  the  ordnance  corps,  with  the  rank  of  lieutenant 
colonel  of  the  United  States  army. 

2.  Q.  What  is  your  residence  and  where  are  you  now  employed? 
A.  I  am  stationed  at  Governor's  island,  New  York  harbor. 

3.  Q.  How  were  you  employed  during  the  war,  as  an  ordnance  officer? 
A.  During  the  war  I  was  in  command  of  Frankfort  arsenal  a  portion 

of  the  time,  and  afterwards  in  command  of  the  Springfield  armory. 

4.  Q.  For  what  length  of  time  and  between  what  dates  were  you  at 
Springfield  armory"? 

A.  Eighteen  months.  I  arrived  there  on  the  27th  of  October,  1864, 
and  left  there  the  middle  of  May,  1866. 

5.  Q.  Have  you  been  engaged  in  testing  heavy  ordnance  at  any  time 
during  the  war? 

A.  I  have.  I  had,  just  before  the  war,  fired  a  pair  of  Eodman  guns 
at  Pittsburg,  and  three  years  ago  I  was  engaged  on  the  board  that 
fired  Mr.  Horatio  Ames's  7-inch  gun. 

6.  Q.  Have  you  also  had  experience  in  the  testing  of  cannon  powder? 
A.  I  have.    While  1  was  at  Frankfort  arsenal  I  was  inspector  of 

powder. 

7.  Q.  Will  you  state  what  the  proper  proportions  of  cannon  powder 
are,  and  what  is  the  standard  proof  powder  used  for  heavy  ordnance? 

A.  Cannon  powder  is  composed  of  saltpetre  75  parts,  charcoal  15 
and  sulphur  10.  The  composition  of  all  powder  is  the  same,  and  varies 
principally  inathe  size  of  the  grains  and  somewhat  in  the  density.  In 
that  for  heavy  guns,  the  size  of  the  grains  is  made  largest.  The  stand- 
ard proof  of  cannon  powder  is :  10  pounds  are  fired  in  an  VIH-inch  gun 
with  solid  shot,  and  the  initial  velocity  is  taken  and  also  the  pressure 
on  the  Square  inch  of  the  bore.  There  are  two  diiferent  kinds  of  powder 
for  cannon :  that  is,  the  cannon  proper  and  mammoth  powder.  The 
cannon  powder  is  used  for  the  larger  guns,  and  for  the  XV-inch  guns  they 
use  rthe  mammoth  powder.  The  initial  velocity  for  the  cannon  powder 
is  about  1,225,  as  I  remember.  It  has  been  some  time  since  I  looked  over 
the  figures.  The  pressure  per  square  inch  is  about  40,000  pounds.  The 


30  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

mammoth  powder  varies  more  than  the  cannon  powder.  It  would  give, 
fired  in  the  VHI-inch  about  1,050  feet  initial  velocity,  and  a  pressure  of 
not  over  10,000  pounds. 

9.  Q.  Do  you  regard  soft  powder  as  suitable  for  large  guns,  to  give 
them  a  proper  velocity  ? 

A.  No,  sir;  soft  powder  would  not  be  suitable  for  large  guns. 

10.  Q.  Is  there  any  difference  in  the  gases,  the  result  of  combustion, 
between  coarse  and  tine  powder  made  from  the  same  constituents  ? 

A.  No,  sir;  I  should  think  not.        t 

11.  Q.  Is  there  any  difference  in  the  quantity  of  gas  resulting  from 
the  com burtion  of  coarse  or  fine  powder? 

A.  I  should  think  not. 

12.  Q.  Which  would  act  with  the  greatest  force  upon  the  square  inch 
of  the  interior  surface  of  the  chamber  filled  with  either  the  coarse  or  fine 
powder,  if  the  chamber  were  strong  enough  to  resist  the  expansion  of 
the  gases? 

A.  The  fine  would  act  with  the  greater  force  on  the  chamber. 

13.  Q.  Is  there  any  residuum  from  powder  which  is  not  combustible? 
A.  O,yes.     • 

14.  Q.  Which  leaves  the  greatest  quantity  of  residuum,  coarse  or  fine 
powder? 

A.  I  should  not  think  there  would  be  any  diiference.  It  is  more  the 
circumstances  under  which  the  powder  is  exploded  than  the  mere  ques- 
tion of.  tli e  size  of  the  grain  that  determines  this. 

15.  Q.  Which  will  project  a  shot  furthest  from  a  XV-inch  gun  coarse 
or  fine  powder,  taking  pound  for  pound? 

A.  The  size  of  the  grain  would  have  to  depend  011  the  density  of  the 
grain.  If  you  made  the  grains  very  large,  then  you  might  make  them 
softer  than  if  you  used  a  smaller  grain.  In  firing  a  XV-inch  gun  the 
point  is  that  you  must  not  endeavor  to  impress  the 'full  strength  of  the 
shot  on  the  powder  too  rapidly.  The  powder  must  burn  progressively, 
giving  the  ball  an  opportunity  to  move  as  the  force  is  gradually  developed. 

16.  Q.  Which  of  those  would  be  furthest  projected  with  the  same 
charge,  in  your  opinion,  solid  or  hollow  shot? 

A.  The  hollow  projectile  would  start  with  a  greater  initial  velocity, 
but  it  would  more  rapidly  lose  its  velocity  than  the  solid  shot.  In  high 
elevations,  with  proper  charges,  the  solid  shot  would  probably  give 
greater  range  than  the  shell. 

17.  Q.  Which,  then,  would  penetrate  the  greatest  thickness  of  plate 
at  a  given  range,  in  your  opinion  ? 

A.  The  penetration  is  a  question  of  the  mass  into  the  square  of  the 
velocity.  That  would  penetrate  the  furthest  vrhere  the  mass  into  the 
square  of  the  velocity  was  greatest.  You  might  arrange  it  so  that  either 
the  shell  or  the  shot  would  penetrate  the  further. 

18.  Q.  Then  hollow  shot  would  be  projected  further  also  if  the  cavity 
were  filled  with  lead,  with  the  same  charge  ? 

A.  That  would  depend  upon  the  charge  you  gave  it.     • 

10.  Q.  With  the  same,  would  the  shell,  if  the  cavity  were  filled  with 
lead,  be  i)rojected  further  than  it  would  be  if  the  cavity  were  not  filled 
with  lead? 

A.  I  think  that  would  depend  very  much  on  what  charge  you  used. 

20.  Q.  Explain  the  distinctinction  you  would  make  in  the  charges  in 
order  to  produce  the  effect  in  one  case  whicji  would  not  be  in  the  other 
as  between  a  small  and  a  large  charge. 

A.  With  a  small  charge  the  hollow  shot  would  probably  go  further 
than  a  very  heavy  projectile  with  the  same  charge,  but  when  you  come 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  31 

to  fire  very  large  charges  then  the  heavier  projectile  would  go  further 
than  the  lighter.  It  is  owing  to  the  fact  that  the  resistance  of  the 
atmosphere  varies  in  a  proportion  rather  greater  than  the  square  of  the 
velocity.  When  the  velocity  increases  very  much,  the  square  runs  up 
very  rapidly,  and  the  retardation  by  the  atmosphere  is  very  great. 
With  a  less  velbcity  it  is  not  so  great. 

21.  Q.  What  force  is  it  that  ejects  the  shot  from  the  gun  ? 
A.  It  is  the  expansive  action  of  the  gases  in  the  gun. 

22.  Q.  In  your  opinion  is  all  that  force  of  the  powder  expended  in 
ejecting  a  hollow  shot  from  a  gun  ? 

A.  That  would  depend  very  much  on  the  length  of  the  bore  and  the 
size  of  the  charge.  You  might  put  in  such  a  charge  that  a  portion  of  the 
powder  would  be  thrown  out  unburned,  as  is  often  the  case. 

23.  Q.  In  your  opinion  is  the  pressure  of  the  powder  per  inch  upon 
'the  interior  surface  greater  with  a  solid  shot  or  with  a  hollow  shot  ? 

A.  The  heavier  the  projectile  the  greater  would  be  the  strain  upon 
the  gun.  , 

24.  Q.  How  heavy,  then,  in  your  opinion,  would  the  projectile  from  a 
XV-inch  gun  have  to  be  in  order  to  attain  the  greatest  result  in  penetra- 
tion of  iron-plating?    Have  your  experiments  led  you  to  a  conclusion 
about  that  ? 

A.  Make  the  mass  into  the  square  of  the  velocity  the  maximum  and 
you  get  the  greatest  penetrative  effect.  That  is,  of  course,  taking  for 
granted  that  your  projectile  has  the  same  figure,  the  same  point.  If  the 
projectile  has  a  different  ppint,  I  mean  front  termination,  that  would 
have  something  to  do  with  the  penetration.  A  round  shot  Avould  not 
penetrate  as  far  as  a  more  pointed  one. 

25.  Q.  Could  you  make  a  projectile,  as  heavy  as  the  gun  itself,  for 
instance,  penetrate  as  great  a  thickness  of  plating  as  a  hollow  shot  of 
the  ordinary  weight  ? 

A.  I  should  not  think  it  would  be  practicable. 

2G.  Q.  You  said  that  you  had  been  engaged  in  the  trial  of  Mr.  Ames's 
guns? 

A.  Yes,  sir. 

27.  Q.  Where  was  it  ? 

A.  At  Bridgeport,  Connecticut. 

28.  Q.  How  many  times  did  you  fire  that  Ames  gun  ! 
A.  Seven  hundred  times. 

29.  Q.  What  charges  of  powder  and  shot  did  you  use  ? 

A.  Charges  varying  from  19  pounds  to  30  pounds,  with  shot  varying 
from  100  to  125  pounds. 

30.  Q.  What  velocities  did  you  get  ? 

A.  It  was  a  difficult  matter  to  obtain  the  velocity,  on  account  of  the 
imperfect  projectiles.  The  base  or  fragments  from  the  projectile  would 
fly  off,  and  cut  the  Avires ;  so  it  was  a  difficult  matter  to  tell  whether  the 
wire  was  cut  by  the  ball  or  cut^by  a  fragment ;  and  on  that  account  we 
did  not  attempt  to  get  the  initial  velocity  with  the  highest  charges. 

31.  Q.  What  were  the  charges? 

A.  Most  of  the  charges  were  with  19  pounds  of  powder.  We  varied 
it,  firing  150  times  with  25  pounds  of  powder,  and  as  many  as  six  times 
with  30  pounds  of  powder.  Most  of  these  were  with  the  powder  known 
in  the  army  as  No.  7  powder,  whi*ch  is  a  smaller  grain  than  cannon. 

32.  Q.  What  was  the  range  of  the  gun  ? 

A.  The  ranges  w^ere  not  determined  very  satisfactorily — fired  over  the 
water  and  determined  by  plane-tables,  I  think.  A  little  over  five  miles 
was  the  greatest  range  we  got. 


32  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

33.  Q.  Had  you  a  base  line  long  enough  to  give  you  the  exact  measure- 
ment of  the  range  ? 

A.  Not  with  great  accuracy ;  and  the  persons  that  were  using  the 
plane-tables  were  not  accustomed  to  the  work. 

34.  Q.  In  your  opinion  the  charges  that  were  used  have  given  a 
greater  velocity  and  range  than  your  figures  in  the  report  made  indicated1? 

A.  I  supposed  that  they  would.  The  gun  was  considerably  worn 
before  the  ranges  were  taken,  and  the  windage  was  greater.  That  would 
cause  a  diminution  of  the  ranges. 

35.  Q.  Would  the  charges,  for  instance  of  30  pounds  of  powder,  give 
you  greater  range  and  velocity  than  the  19-pound  charges? 

A.  It  is  fair  to  suppose  so.    Yes,  sir ;  I  should  think  so. 

36.  Q,  That  was  the  firing  in  1864,  was  it  not? 
A.  Yes,  sir. 

37.  Q.  What  was  the  size  of  that  gun? 

A.  It  had  a  7-inch  bore,  and  weighed  about  19,400  pounds. 

38.  Q.  Did  you  superintend  the  firing  of  the  Ames  gun  in  1866 — the 
100-pounder? 

A.  I  was  associated  with  Commodore  Hunt  in  the  proof  of  that  gun 
also. 

39.  Q.  Had  the  powder  been  proved  that  was  used  in  that  trial  ? 
A.  Yes,  sir. 

40.  Q.  What  pressure  on  the  gun  did  that  powder  give,  and  what  velo- 
city? 

A.  I  do  not  remember  the  velocity.  I  remember  that  the  pressure  of 
one  of  the  powders  used  was  87,000  pounds  per  square  inch.  That  was 
not  the  powder  used  in  1864. 

41.  Q.  What  was  the  difference  between  the  powder  used  in  1864  and 
that  used  in  the  100-pounder  in  1866? 

A.  The  powder  used  in  1866  was  a  much  quicker  powder,  and  pro- 
duced a  much  greater  strain  on  the  gun  than  that  used  in  1864. 

42.  Q.  What  range  did  that  100-pounder  give  in  1866? 

A.  The  ranges  of  that  were  extremely  unsatisfactory.  We  had  three 
stations;  and  the  ranges  as  given  by  the  two  stations  did  not  correspond 
with  each  other;  and  I  do  not  remember  what  the  range  was.  I  remem- 
ber the  fact  that  they  were  very  unsatisfactory.  I  was  in  favor  of  trying 
it  over. 

43.  Q.  Was  the  measurement  unsatisfactory  to  you,  or  the  range  shown 
by  the. gun? 

A.  We  had  three  observers,  either  two  of  which  would  make  a  com- 
plete set  of  results;  and  then,  with  the  three  observers,  we  ought  to 
have  three  separate  and  distinct  ranges.  If  the  experiments  were  accu- 
rately conducted  those  three  would  have  agreed  very  closely.  They  did 
not  agree,  but  varied  so  much  as  to  create  doubt  of  their  accuracy. 

44.  Q.  Bo  you  think  the  rifling  of  that  100-pounder  was  suitable 
rifling  for  a  gun  of  that  calibre? 

A.  I  do  not;  I  do  not  think  the  twist  was  quick  enough. 

45.  Q.  Do  you  think  the  range  would  have  been  greater  with  a  greater 
twist  in  the  rifling?  • 

A.  I  think  we  might  have  got  a  chance  shot  with  this  gun  where  the 
range  might  have  been  as  great  as  it  would  have  been  with  a  quicker 
twist,  because  the  friction  would  be  less;  but  the  twist  was  not  sufficient 
in  all  cases  to  keep  the  ball  point  foremost;  and  in  that  case  the  range 
ordinarily  would  not  be  as  great  as  it  would  be'  with  a  quicker  twist. 

46.  Q.  Did  you  fire  the  gun  at  a  high  elevation? 
A.  We  did;  as  high  as  the  carriage  would  admit. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  33 

47.  Q.  Are  you  accustomed  to  fire  guns  at  so  high  an  elevation  in  proof? 
A.  We  do  not  ordinarily  do  it  in  proof? 

48.  Q.  Why  did  you  fire  at  so  very  high  an  elevation  at  that  time  ? 
A.  For  the  purpose  of  obtaining  the  range  ? 

49.  Q.  The  elevation  at  which  you  fired  that  gun  is  a  stronger  proof 
than  you  ordinarily  subject  guns  of  any  kind  to,  is  it  not? 

A.  Actual  experiment  does  not  show  that  the  strain  is  very  much 
increased  by  increasing  the  elevation.  The  ordnance  department  made 
a  series  of  experiments  at  Old  Point  Comfort  with  a  view  of  testing  that, 
and  found  the  additional  strain  on  high  elevations  is  very  trifling. 

50.  Q.  You  think  that  experiment  or  experience  does  not  prove  that 
it  makes  any  very  great  difference. 

A.  Those  are  the  actual  experiments  performed  by  the  ordnance 
department,  by  the  pressure  plug.  Those  are  the  results  given  by  the 
pressure  plug. 

51.  Q.  How  many  of  those  100-pounders  were  you  on  a  commission  to 
examine? 

A.  I  think  there  were  nine  or  thirteen,  I  am  not  sure  which. 

52.  Were  the  guns  fired  in  1864  and  those  fired  in  1866  of  precisely  the 
same  calibre? 

A.  There  was  only  one  fired  in  1866. 

53.  Q.  You  were  on  a  commission  to  examine  how  many  of  them? 

A.  I  am  not  sure  whether  there  were  nine  or  thirteen.  They  were 
7-inch  guns  ordered  by  Mr.  Lincoln. 

54.  Q.  I  was  under  the  impression  there  were  three  or  four  tested  in 
1866? 

A.  In  1866  we  fired  a  single  gun,  at  Bridgeport. 

55.  Q.  That  represented  how  many  of  these  guns — eight  or  nine? 
A.  I  am  not  sure  about  that.    Those  were  navy  guns. 

56.  Q.  State  in  general  terms  what  your  report  was. 

A.  We  reported  that  the  Ames  gun,  when  the  welds  were  well  made, 
was  a  stronger  gun  than  any  that  had  ever  been  presented  in  the  ser- 
vice; that  we  did  not  fire  them  all,  and  were  therefore  not  prepared  to 
say  whether  the  other  guns  were  good  guns  or  not;  that  we  could  not 
pretend  to  say,  from  firing  one  gun,  what  would  be  the  quality  of  the  guns 
that  had  not  been  tested  at  all;  and  stated  that  it  would  be  necessary 
to  fire  them  before  we  could  determine  upon  their  merits;  after  they  had 
been  fired  to  test  their  strength,  we  thought  they  ought  to  be  tested  by 
firing  service  charges  to  ascertain  their  durability. 

57.  Q.  You  of  course  did  not  feel  authorized  to  go  into  any  question 
that  might  arise  under  the  contract  for  making  the  guns? 

A.  We  were  not  called  upon  to  decide  any  question  of  that  kind. 

58.  Q.  Did  you  mean  that  your  condemnation  of  the  guns  should 
touch  the  question  whether  they  should  be  paid  for  or  not — whether  Mr. 
Ames  was  entitled  to  be  paid  for  them  ? 

A.  Not  at  all. 

59.  Q.  Is  it  possible,  in  your  opinion,  to  make  a  weld  of  a  wrought- 
iron  gun  so  perfect  that  it  will  not  be  a  weak  spot  in  the  gun? 

A.  I  think  it  can  be  done. 

60.  Q.  What  do  you  think,  then,  of  the  principle  of  manufacturing 
guns  as  Mr.  Ames  has  undertaken  it? 

A.  I  do  not  know  whether  Mr.  Ames  can  make  a  perfect  weld  uni- 
formly or  not  in  such  large  masses. 

61.  Q.  Then,  when  you  say  that  you  think  a  weld  can  be  made  so  perfect 
as  not  to  leave  a  weak  place  in  the  gun,  you  have  no  experience  that 
would  extend  that  to  very  large  guns? 

Rep.  No.  266 3 


34  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  No,  sir ;  for  instance,  we  weld  musket  barrels  successfully,  though 
we  do  come  to  one  occasionally  that  is  not  welded. 

62.  Q.  Are  you  led  to  believe  that  a  weld  in  the  construction  of  a  gun 
so  large  as  these  100-pounders  can  be  made  so  perfect  as  not  to  leave  a 
weak  spot  in  the  gun? 

A.  It  can  be  done  ;  but  whether  it  can  be  done  every  time  or  not  I  do 
not  know.  For  instance,  in  the  3-inch  guns  we  weld  the  trunnions  on  to 
the  body  of  the  gun.  I  never  knew  one  to  give  way  there. 

63.  Q.  It  is  usual,  at  least  in  the  naval  system  of  ordnance,  and  per- 
haps with  the  army,  to  accept  guns  upon  a  trial  of  one  of  the  lot.    If  it 
stands  the  test,  is  not  the  lot  received  without  trying  each  gun  ? 

A.  In  the  land  service  we  fire  each  gun ;  but  we  do  not  fire  it  to 
extremity. 

64.  Q.  You  do  not  submit  each  gun  to  the  great  trial  test  of  a  thousand 
rounds,  for  instance? 

A.  O,  no.  With  cast-iron  guns  they  take  one  gun  and  fire  it  a  thousand 
rounds,  and  then  afterwards  make  others  as  nearly  like  that  as  it  is  pos- 
sible to  make  them,  and  accept  them  on  a  very  trifling  proof. 

65.  Q.  You  think,  then,  in  the  case  of  wrought-iron  guns  it  is  more 
important  than  even  in  the  case  of  cast-iron  guns  to  submit  every  gun  to 
a  test? 

A.  I  think  it  would  be  necessary  to  give  each  individual  gun  a  more 
severe  test  than  in  the  case  of  cast  iron. 

66.  Q.  And  to  give  a  thorough  test  to  each  gun  before  you  would 
condemn  or  accept  it  ? 

A.  I  would  pursue  very  much  the  same  course  we  do  with  the  musket 
barrel.  Every  one  we  adopt  we  fire  with  an  excessive  charge,  in  order 
to  test  the  question  whether  it  is  welded  or  not.  If  it  is  not,  it  gives 
way.  If  it  is  thoroughly  welded,  it  does  not  give  way.  I  think  it  would 
lie  necessary,  in  proving  wrought-iron  guns,  to  fire  each  one  with  an 
excessive  charge  to  test  that  question,  whether  it  was  welded  perfectly 
or  not. 

67.  Q.  What  gun  have  you  ever  ,tried,  if  any,  that  you  think  equal  to 
this  Ames  gun? 

A.  I  have  never  fired  any  gun  so  large  as  the  Ames  gun  which  I  think 
possesses  as  much  strength  as  the  one  that  we  tested.  I  fired  a  small 
gun  made  of  wire  by  Dr.  Woodbridge,  which  I  think  probably  was  as 
strong  in  proportion  as  Mr.  Ames's  gun.  But  that  was  a  very  small  gun. 

68.  Q.  Could  that  system  of  manufacture  be  applied  to  very  large 
guns? 

A.  The  inventor  thinks  it  can. 

69.  Q.  I  am  asking  for  your  own  opinion  ? 

A.  I  do  not  know ;  have  not  sufficient  information  to  give  an  opinion 
on  the  question. 

70.  Q.  The  Ames  guns  are  the  largest  wrought-iron  guns  you  have 
ever  tried? 

A.  They  are. 

71.  Q.  Are  you  well  acquainted  with  the  Parrott  gun  ? 

A.  I  have  had  very  little  experience  with  the  Parrott  gun. 

72.  Q.  Have  you  never  tested  any  of  them? 
A.  I  have  never. 

73.  Q.  Do  you  suppose  that  a  Parrott  gun  of  the  same  calibre  would 
stand  20-pounds  charges  10  times  with  the  same  powder  you  used  in  the 
trial  of  the  Ames  guns,  giving  87,000  pounds  pressure  on  the  bore  of  the 
gun? 

A.  I  do  not  think  it  would. 


EXPERIMENTS    ON    HEAVY    ORDNANCE.  35 

74.  Q.  What  would  be  the  comparative  difference  of  velocity,  as  given 
by  the  20-pounds  charge  and  the  10-pounds  charge  of  powder? 

A.  I  00  not  think  you  could  get  any  rule. 

75.  Q.  Do  you  think  there  was  any  difficulty  as  to  the  range,  arising  from 
the  kind  of  powder  that  was  used  in  those  experiments  at  Bridgeport  ? 

A.  No ;  I  should  think  not.  At  the  experiments  in  1864  we  used  two 
kinds  of  powder,  both  No.  7  and  No.  5. 

76.  Q.  Was  there  nothing  in  the  character  of  the  powder  used  giving 
it  a  greater  tendency  to  burst  the  gun  than  powder  ordinarily  used! 

A.  In  1866  the  powder  was  a  very  bursting  powder;  but  if  the  gun 
should  resist  it  as  it  did,  there  was  so  much  of  it,  I  should  think  it  ought 
to  give  a  very  high  velocity  and  great  range* 

77.  Q.  It  was  in  1866  that  you  used  a  powder  appertaining  more  to 
the  character  of  a  fulminating  powder  than  the  other? 

A.  Yes,  sir. 

78.  Q.  I  think  you  stated  that  you  did  not  think  this  Ames  gun  had 
the  best  rifling  to  adapt  it  to  the  greatest  range  or  effectiveness? 

A.  I  did. 

79.  Q.  What  change  would  you  have  suggested  in  that  rifling? 

A.  I  would  have  made  it  quicker — given  more  rotary  motion  to  the  ball. 

80.  Q.  Did  you  ever  have  anything  to  do  with,  or  suggest,  rifling  of 
that  kind? 

A.  Nothing. 

81.  Q.  Do  you  know  who  directed  the  rifling? 

A.  I  do  not  know.  I  understood  the  government  ordered  the  rifling, 
but  I  do  not  know  that  to  be  the  case  from  my  own  personal  knowledge. 

82.  Q.  Are  you  acquainted  with  the  Armstrong  gun?  v 
A.  Only  from  books  and  newspapers. 

83.  Q.  Do  you  consider  thztt  better  than  any  gun  we  have? 
A.  I  do  not  think  it  as  strong  a  gun  as  Mr.  Ames's  gun. 

84.  Q.  What  would  be  your  opinion  of  the  comparative  merits  of  a  9- 
inch  rifled  gun  and  a  6^  calibre  gun,  loaded  with  proportionate  charges, 
fired  as  against  an  enemy,  when  fired  at  the  highest  velocity  ? 

A.  It  all  narrows  itself  down  to  the  proposition  I  have  already  stated, 
one-half  the  mass  into  the  square  of  the  velocity  is  the  work  done.  It 
all  depends  on  that. 

85.  Q.    It   is  your  opinion    all  these   questions  can  be  settled  with 
mathematical  accuracy  without  reference  to  experience  and  whatever 
we  learn  by  the  practical  use  of  the  guns  ? 

A.  Captain  Noble,  of  the  English  service,  has  made  a  series  of  exper- 
iments, and  finds  that  you  can  calculate  with  very  considerable  accuracy 
the  effect  of  any  shot.  We  feel  much  more  sure  of  all  these  tests,  of 
course,  after  we  have  had  the  actual  experiment  performed.  But  the 
English  government  has  made  a  large  series  of  experiments,  and  that  is 
the  conclusion  Captain  Noble  comes  to — that  we  can  calculate  with  very 
great  accuracy  the  effect  of  any  shot  projected  with  any  given  initial 
velocity. 

86.  Q.  Have  we  any   rifled  gun  that  can   stand  charges   that  will 
give  the  greatest  velocity  to  the  shot  of  8,  9,  or  10-inch  calibre? 

A.  We  have  no  rifled  guns  in  the  service  that  I  know  of  except  the 
Parrott  guns  and  some  experimental  cast-iron  guns  of  8  and  12-inch 
bore.  It  has  not  yet  been  tested  thoroughly  what  endurance  these  guns 
will  have  under  high  charges. 

87.  Q.  I  was  asking  for  your  opinion.    Do  you  believe  we  have  any 
gun,  say  from  8  to  10-inch  calibre,  that  is  strong  enough  to  resist  the 
charges  that  will  give  the  greatest  velocity  to  the  shot  ? 

A.  I  do  not  think  we  have. 


• 
36  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

88.  Q.  I  suppose  it  is  your  opinion  that  is  very  desirable  ? 
A.  O,  very. 

89.  Q.  Do  I  understand  you  to  say  this  Ames  gun  is  the  strongest 
that  you  have  ever  tested,  tried,  or  know  anything  about  1 

A.  When  the  welds  are  well  made  it  is  the  strongest  gun  I  have  ever 
known. 

90.  Q.  Did  you  ever  send  more  than  one  sample  of  the  powder  used 
in  these  experiments  to  Captain  Belief? 

A.  I  sent  him  a  sample  of  each,  and  the  intention  was  there  should 
be  enough  to  fire  three  rounds  of  each  powder.  The  powder  used  is 
known  as  No.  7  experimental  powder,  of  57,000  pounds  per  square  inch. 
(It  is  erroneously  printed  in  the  report  5,700  pounds.) 

91.  Q.  You  say  you  sent  a  specimen  of  each ;  do  you  mean  that  used 
in  1864  and  that^used  in  1806  ? 

A.  Yes,  sir ;  we  usually  send  samples  enough  to  fire  three  charges. 
We  sent  samples  enough  to  fire  three  rounds  of  that  in  1864,  and  the 
same  of  that  in  1866.  Wliat  we  used  in  1864  was  all  the  same;  but 
whether  the  powder  used  in  1866  was  all  the  same  I  cannot  say. 

92.  Q.  What  is  the  proof  reported  to  you  by  Captain  Bene'tf 
A.  Eighty-seven  thousand  pounds  per  square  inch. 

93.  Q.  Do  you  consider  the  kind  of  powder  you  used  in  1866  suitable 
powder  to  use  in  a  gun,  except  it  be  to  see  whether  you  cannot  burst  it  ? 

A.  I  do  not. 

94.  Q.  It  is  not  such  powder  as  you  would  use  in  practice  at  all  ? 
A.  No,  sir. 

95.  Q.  It  was  used,  then,  as  an  extreme  fulminating  powder,  in  order 
to  produce  the  greatest  strain  ? 

A.  I  cannot  say  what  it  was  used  for.  The  powder  was  supplied,  and 
I  was  merely  sent  there  to  assist  Commodore  Hunt  in  the  firing. 

96.  Q.  What  is  the  standard  proof  of  powder  used  in  the  army  for 
velocity  and  pressure  on  the  bore  of  the  gun  ? 

A.  Our  cannon  powder  should  not  give  a  pressure  higher  than  about 
40,000  pounds  per  square  inch. 

97.  Q.  Do  you  know  what  the  rule  is  in  the  navy? 

A.  I  do  not  think  in  the  navy  they  take  into  consideration  the  pressure 
on  the  bore,  though  I  cannot  state  certainly. 

98.  Q.  You  speak  of  the  diificulty  of  making  a  weld,  in  the  construc- 
tion of  a  large  gun  like  this,  so  perfect  as  not  to  leave  a  weakness  in  the 
gun  at  that  point ;  I  will  ask  you  whether  the  fissures  or  cracks  in  a  gun 
made  by  welding  together  wrought  iron  are,  in  your  opinion,  always 
the  result  of  imperfection  in  the  welding,  or  whether  they  are  not  as 
likely  to  be  produced  by  the  unequal  contraction  of  the  iron  in  the  mass 
of  the  gun  ? 

A.  We  never  discovered  any  fissures  except  rings,  and  I  supposed 
those  were  caused  in  all  cases  by  imperfect  welds. 

99.  Q.  If  there  was  unequal  contraction  in  cooling  of  one  of  these  rings, 
might  it  not  produce  a  fissure  ? 

A.  I  do  not  see  how  it  could  produce  a  fissure  such  as  we  found.  The 
guns  were  manufactured  by  a  series  of  rings  put  together  one  on  top  of 
the  other. 

100.  Q.  Might' there  not  be  a  difference  in  the  density  of  the  metal  of 
different  parts  of  the  same  ring  I 

A.  There  might  be. 

101.  Q.  Would  not  that  produce  unequal  contraction  when  the  ring 
came  to  cool? 

A.  It  would. 


EXPEKIMENTS    ON    HEAVY    ORDNANCE.  37 

102.  Q.  If  in  consequence  of  contraction  there  was  an  opening  of  the 
seam,  making  a  fissure,  or  a  giving  way  of  the  metal  anywhere,  would 
it  not  be  more  likely,  in  your  opinion,  to  be  at  the  point  where  the  two 
rings  met  and  the  weld  took  place  than  at  any  other  ? 

A.  I  do  not  see  that  it  would.  It  is  understood  that  the  gun  is  actu- 
ally forged  hollow,  and  has  an  opportunity  to  contract. 

103.  Q.  When  you  speak  of  the  pressure  of  powder  on  the  square 
inch  will  you  state  what  instrument  you  use  for  determining  that  pressure  1 

A.  We  use  what  is  known  as  Bodman's  pressure  piston.  It  is 
described  in  the  Ordnance  Manual. 

104.  Q.  Do  you  think  that  a  reliable  or  infallible  instrument  for  such 
measure  ? 

A.  I  do  not  think  it  is  infallible.    It  is  the  best  that  we  have. 

105.  Q.  Does  that  give  the  pressure  actually,  or  what  you  call  the 
momentum  of  the  gases? 

A.  There  is  a  difference  of  opinion  about  that. 

106.  Q.  I  want  yours. 

A.  I  think  it  gives  it  very  nearly.  It  is  undoubtedly  the  momentum 
of  the  part  of  the  piston  that  moves ;  but  the  distance  this  piston  travels 
is  very  small. 

107.  Q.  Capable  of  being  observed,  though,  accurately? 
A.  O,  yes. 

108.  Q.  Did  I  understand  you  to  say  that  the  velocity  and  range  were 
not  determined  by  the  highest  charges  that  you  used  ? 

A.  The  velocity  was  not  determined  by  the  highest.    The  range  was. 

109.  Q.  Was  the  velocity  or  was  the  range,  either  or  both  of  them, 
greater  for  the  larger  charges  that  were  used  in  these  experiments'? 

A.  We  only  determined  the  initial  velocity,  I  think,  for  the  19  pounds 
of  powder,  not  for  the  larger  charges.  Owing  to  the  difficulty  which  I 
speak  of,  the  fragments  of  the  shell  flying  oif  and  breaking  the  wires, 
we  did  not  regard  it  as  reliable,  and  therefore  gave  it  up. 

110.  Q.  Do  you  know  anything  about  the  experiments  with  the  Par- 
rott  guns  at  Charleston,  and  the  practical  use  of  them  there! 

A.  I  do  not,  except  what  I  have  read  or  heard — nothing  from  actual 
knowledge. 

111.  Q.  Do  you  know  whether  the  velocity  obtained  with  these  experi- 
ments with  this  gun  was  greater  than  that  obtained  at  Charleston  from 
the  Parrott  gun  with  smaller  charges,  with  the  same  elevation? 

A.  You  can  but  know,  or  think,  at  any  rate,  it  was  greater,  because 
the  charges  at  Charleston  must  have  been  less. 

112.  Q.  Were  the  samples  of  powder  sent  by  you  to  Captain  Benet 
the  same  that  were  used? 

A.  They  were. 


WASHINGTON,  D.  C.,  November  12,  1867. 

NORMAN  WIARD  re-called. 
By  Mr.  CAMERON  : 

Question.  Do  you  know  what  varieties  of  calibres  and  ammunition 
were  introduced  in  the  service,during  the  war,  and  have  you  any  opinion 
as  to  the  importance  of  establishing  a  uniformity  of  calibres  and  ammu- 
nition ? 

Answer.  I  am  familiar  with  the  calibres  of  our  guns ;  and  when  I  relate 
some  of  the  facts  within  my  knowledge  I  think  you  will  agree  with  me 
that  our  ordnance  departments  have  got  our  small-arms,  artillery  and 


38  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

guns  into  most  reprehensible  confusion,  for  want  of  uniformity  in  calibre 
and  ammunition.  The  ordnance  departments  of  France  and  England 
have  no  greater  differences  embodied  in  the  systems  they  have  adopted 
than  there  is  between  the  two  branches  of  our  service.  The  calibres, 
models,  chambers,  and  ammunition  of  the  navy  are  utterly  unlike  those 
adopted  for  the  army.  The  navy  rifled  12-pounder  boat  howitzer  has  a 
calibre  of  3  ^  inches,  while  the  army  12-pounder  rifled  guns  are  of  the 
calibres  of  3  inches,  3T2^  inches,  3^,  inches,  and  3 y^  inches.  The  navy 
12-pounder  has  a  parabolic  form,  of  chamber,  while  the  army  gun  has 
either  no  chamber  or  it  is  cycloidal.  The  navy  12-pounder  smooth-bore, 
although  of  the  same  calibre  as  the  army  gun,  has  a  different  form  of 
chamber.  Apparently  each  of  these  chambers  has  been  devised  to  prevent 
the  use  of  navy  ammunition  in  the  army  gun  or  army  ammunition  in  the 
navy  gun.  The  models  of  the  two  guns  are  entirely  different,  and  neither 
will  go  on  the  other's  carriage,  the  army  gun  being  furnished  with  trun- 
nions and  the  navy  gun  having  the  loop  and  loop  bolt  of  the  old  carro- 
nade.  The  sights  are  of  an  entirely  different  kind  in  the  two  guns,  and 
so  graduated  as  to  make  it  impossible  for  a  navy  gunner  to  use  an  army 
gun,  or  an  artillerist  of  the  army  to  use  a  navy  gun  for  an  emergency — 
one  being  graduated  to  seconds  of  time  and  the  other  to  degrees  of  eleva- 
tion. The  20-pouuders  and  30-pounders  of  the  navy  are  different  from 
the  army  guns  of  the  same  kind,  the  navy  guns  having  a  shark's  mouth 
for  the  breeching,  which  is  not  on  the  army  guns.  The  navy  Dahlgren 
20-pounder,  30-pounder  and  50-pouiider  are  of  a  different  model,  calibre, 
form  of  chamber,  and  kind  of  rifling  from  any  other  gun  in  the  navy  or 
army,  all  purposely  different,  seemingly,  to  insure  the  use  of  a  certain 
kind  of  projectile  which  Captain  Dahlgren  claimed  to  have  invented, 
being  essentially  the  same  as  the  so-called  Dyer  projectile,  but  which 
was  found  latterly  to  have  been  used  and  patented  by  others  long  before. 
The  Dahlgren,  like  the  Dyer,  was  abandoned  after  large  numbers  of 
them  had  been  produced.  The  Dahlgren  50-pounder  has  a  calibre  of  5  JL 
inches,  as'  if  the  inventor,  from  paucity  of  ideas,  could  only  produce  a 
new  diameter  of  calibre  which  no  other  person  had  thought  of. 

The  army  3  inch  gun,  it  has  been  said,  was  rifled  in  a  peculiar  way  to 
adapt  it  to  the  Dyer  projectile,  which  being  condemned,  it  was  happily 
found  could  be  used  with  the  Hotchkiss  projectile.  The  navy  have,  then, 
a  60-pound er  Parrott,  adopted,  as  shown  by  the  lucid  explanation  of  Cap- 
tain Wise,  Chief  of  Ordnance,  so  as  to  have  something  between  the  30- 
pounder  and  the  100-poimder;  and  no  other  reason  is.  given  for  its  adop- 
tion !  The  navy  has  VHI-inch,  IX-inch,  Xl-inch  and  XHI-inch  smooth- 
bores, as  if  the  navy  chose  odd  numbers  of  inches  for  luck.  The  army 
sm  oo th-bores  are  6-inch,  (32-pounders,)  8-inch  (64-pounders,)  and  10-inch, 
(130-pounders.)  The  navy  chose  the  old  Konian  numerals  to  describe  the 
calibres  of  their  guns,  probably  because  the  army  had  some  fanciful  pre- 
emption right  to  the  more  common  figures.  In  the  guns  adopted  and 
actually  issued  to  service  in  the  two  branches  of  the  service,  there  is  not 
a  single  example  of  uniformity,  in  either  rifle  or  smooth-bore,  in  the 
20  calibres  adopted  of  those  below  the  calibre  of  the  30-pounder.  I  append 
a  tabulated  statement  of  calibres,  models,  weights,  chambers  and  charges. 

How  long  it  has  taken  two  complete  organizations  of  ordnance  officers, 
educated  at  the  public  expense,  experimenting,  with  the  treasury  of  the 
United  States  to  pay  the  bills ;  what  the  cost  of  the  effort  has  been  in 
money ;  how  much  treasure  has  been  wasted  in  furnishing  the  arms  to  the 
extent  to  which  they  have  been  supplied  after  they  were  adopted  ;  how 
much  life  of  citizen  soldiers  and  honor  of  the  nation  have  been  misdi- 
rected and  wasted,  it  is  not  within  my  power  to  even  estimate.  I  am, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.         /  39 

however,  confident  that  no  example  of  such  imbecility  of  invention  and 
paucity  of  practical  results  ever  before  attended  an  effort  conducted  with 
so  much  flourish,  on  so  grand  and  expensive  a  scale,  with  objects  so 
important,  and  where  the  class  of  persons  charged  with  so  important  a 
branch  of  the  public  service  for  so  many  critical  years  have  brought  their 
departments  into  such  confusion.  They  are  entitled  to  the  execrations 
of  every  citizen,  and  would  receive  them,  too,  were  the  facts  known. 

The  calibres  of  small-arms  and  the  ammunition  for  them — although  it 
would  seem  impossible,  so  minute  must  be  the  differences  where  the 
greatest  is  .70  of  an  inch — are  as  diverse  as  in  the  field,  siege  and  heavy 
guns,  and  similar  want  of  uniformity  exists.  In  order  to  find  divisions 
for  sufficient  diversity  the  dimensions  of  calibres  are  given  inhundredths 
or  thousandths  of  an  inch,  and  our  muskets  and  carbines  alone  range* 
from  .40  to  .69  We  have  an  Enfield  rifle  of  .57  and  a  Springfield  of  .58, 
but  no  instruments  common  in  the  hands  of  inspectors  or  soldiers  for 
determining  the  difference.  Hence,  during  the  war  the  army  has  fre- 
quently found  itself  on  the  field  of  battle  facing  the  enemy  with  ammu- 
nition one-hundredth  of  an  inch  too  large  to  be  inserted  in  the  gun. 
About  20  different  calibres  of  ammunition  were  furnished  the  Burnside 
expedition,  from  .44  to  .69;  and,  lest  one  transport  carrying  all  of  one 
calibre  should  be  lost,  each  vessel  had  to  be  supplied  with  an  assorted 
cargo  made  up  of  certain  proportions  of  the  whole.  It  was  the  same  with 
the  Banks  expedition,  making  it  necessary  to  stow  away  the  cargo  with 
considerable  skill,  so  that  any  of  the  various  kinds  could  be  got  at  upon 
the  recurrence  of  an  emergency,  a  ]1reliminary  caution  likely  to  be  over- 
looked in  the  hurry  of  the  embarcation  of  an  army;  the  consequences  of 
neglecting  which — and  no  cautionary  order  by  the  ordnance  department 
is  given  on  such  an  occasion — are  easy  to  conceive.  A  great  many  hun- 
dred thousands  of  Springfield  muskets  are  now  to  be  sacrificed  to  uni- 
formity of  calibre.  The  ordnance  department  in  this,  as  in  the  question 
whether  it  was  better  to  have  breech  or  muzzle  loaders,  were  undecided 
during  the  war,  only  concluding*1  their  cogitations  when  the  emergency 
had  passed.  In  1861,  when  every  tyro  knew  that  a  breech-loader  was 
best — in  fact  nobody  but  an  idiot  or  an  officer  of  our  ordnance  depart- 
ment would  ever  decide  otherwise — the  Chief  of  Ordnance  of  the  United 
States  held  and  advocated  that  "a  Harper's  Ferry  smooth-bore  muzzle- 
loading  gun,  with  buck  and  ball,  was  the  best  arm  that  could  be  placed 
in  the  hands  of  a  soldier;-'  and  asserted  he  would  have  no  such  gun  as  a 
breech-loader  in  service  because  it  would  require  a  mule  to  carry  the 
ammunition  for  each  soldier — it  would  be  shot  away  so  fast !  Now  it  is 
proposed  to  alter  all  the  Springfield  rifles  on  hand  to  breechloaders; 
and  in  order  to  get  uniformity  of  calibre,  i.  e.,  to  have  the  musket  con- 
form to  the  calibre  of  the  carbine,  the  barrel  is  to  be  reamed  out,  another 
barrel  inserted,  the  new  lining  is  to  be  bored  out,  straightened  and  rifled ; 
the  breech  of  the  barrel  is  to  be  bedevilled  by  the  insertion  of  a  compli- 
cation of  parts,  and  thus  a  new  gun  is  to  be  made.  But,  gentlemen,  this 
will  cost  more  than  to  make  a  new  gun;  and  that  is  not  all,  for  although 
it  is  an  approach  to  uniformity  of  calibre,  it  brings  us  no  nearer  to  uni- 
formity of  ammunition  than  we  were  before,  because  the  carbine  charge 
is  not  sufficient  for  the  musket,  and  when  this  improvement  is  adopted 
we  shall  have  another  slight  diversity,  as  in  the  case  of  the  Enfield  of 
.57  and  the  Springfield  of  .58,  for  the  chamber  of  the  carbine  is  not  long 
enough  for  the  musket  cartridge,  and  the  carbine  charge  is  not  heavy 
enough  for  the  breech-loading  musket. 


40  EXPERIMENTS   ON   HEAVY    ORDNANCE. 

WASHINGTON,  November  12,  1867. 
Q.  A.  GILLMORE  sworn  and  examined. 

By  the  CHAIRMAN  pro  tern. : 

1.  Question.  Will  you  state  if  you  are  in  the  military  service  of  the 
United  States ;  if  so,  in  what  arm  of  the  service  and  with  what  rank  ? 

Answer.  1  am  in  the  service  of  the  United  States,  major  in  corps  of 
engineers  and  brevet  major  general  in  the  United  States  army. 

2.  Q.  Were  you  in  command  at  the  siege  of  Charleston  ? 

A.  Yes,  sir  j  in  command  of  the  besieging  forces.  After  the  April 
attack  by  the  navy  I  had  command  of  the  land  forces. 

Will  you  state  how  many  men  composed  your  army  and  what  was  the 
plan  of  attack  there  ? 

When  I  assumed  command  in  June,  1863,  I  found  the  troops  occupy- 
ing the  coast  from  St.  Augustine,  Florida,  to  the  north  end  of  Folly 
island.  I  got  together  10,000  men  in  round  numbers,  for  offensive  ope- 
rations, leaving  the  most  important  points  of  the  coast  garrisoned  in 
sufficient  force  for  security.  The  plan  of  operations  was  to  make  a 
descent  upon  Morris  island,  carry  its  defences  by  assault  or  siege,  and 
then  demolish  Fort  Sumter  so  that  the  navy  could  enter  the  near  harbor 
and  move  up  to  the  city.  A  siege  of  Charleston  by  land  was  never  con- 
templated in  my  instructions  or  in  any  of  my  plans.  This  plan  the 
General-in-chief  informed  me  grew  out  of  a  request  by  the  naval  authori- 
ties for  assistance  in  making  another  attack  upon  Charleston.  They 
desired  Fort  Smnter,  which  had  repulsed  them  in  April,  to  be  eliminated 
from  the  fight. 

By  Mr.  CAMERON  : 

3.  Q.  What  sort  of  gnns  had  you  there  in  use  ? 

A.  All  the  heavy  guns  were  Parrotts ;  I  had  field  batteries  besides. 

4.  Q.  What  were  the  charges  used  in  the  different  calibres  of  these 
guns  ? 

A.  I  do  not  recollect  j  I  used  the  charges  prescribed  by  Mr.  Parrott, 
if  that  would  be  an  answer,  in  all  cases. 

5.  Q.  What  powder  did  you  use  in  the  100,  200,  and  300-pounders  ? 
A.  We  called  it  "  cannon"  powder.    It  was  not  mammoth  powder.    I 

think  we  had  a  little  mammoth  powder  for  a  few  trials,  but  we  used 
cannon  powder. 

6.  Q.  Was  that  furnished  you  I 

A.  Yes,  sir ;  furnished  us  by  requisition  on  the  Chief  of  Ordnance. 

7.  Q.  What  is  the  velocity  and  pressure  on  the  bore  of  the  gun  with 
this  powder  ? 

A.  I  cannot  tell  you  that. 

8.  Q.  Can  you  tell  me  what  'does  No.  7  powder  give  I 
A.  No,  sir. 

9.  Q.  Nor  No.  5  ? 

A.  No,  sir ;  that  requires  a  technical  knowledge  which  I  do  not  pos- 
sess just  now.  I  have  known  at  various  times,  but  I  forget  it.  The 
smaller  the  powder  the  greater  the  pressure  generally ;  but  I  do  not 
recollect  the  pressure  in  pounds. 

10.  Q.  What  range  did  you  get  from  100,  200,  and  300-pounders  I 

A.  The  200-pounder  fired  from  Morris  island  to  the  city  of  Charleston. 
I  should  have  to  refer  to  my  report  to  see  the  number  of  yards.  I  only 
know  it  was  over  7,000  yards,  because  we  had  means  of  knowing  that 
the  projectiles  went  into  the  city,  and  it  was  7,000  yards  to  the  nearest 
point. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  41 

11.  Q.  Did  they  go  into  the  city  to  be  effective  ? 

A.  The  shells  from  the  first  gun  we  fired  went  through  houses ;  did 
not  accomplish  any  immediate  military  effect. 

12.  Q.  What  is  the  cost  of  placing  a  "  Swamp  Angel"  for  use? 

A.  It  is  difficult  to  give  the  cost  of  the  battery.  There  were  $4,000 
worth  of  sand-bags  used  in  it.  That  was  the  only  material  I  had  to 
buy.  The  timber  we  cut  in  the  woods  on  the  adjoining  island  and 
carried  up  there. 

13.  Q.  What  time  did  it  occupy  ? 

A.  It  occupied  about  three  weeks,  I  think. 

14.  Q.  And  how  many  men  were  employed  at  it  1 

A.  I  suppose  there  were  two  or  three  parties  of  fifteen  or  twenty  men 
apiece  ;  some  carrying  sand-bags,  some  floating  logs  down  to  the  place, 
some  cutting  logs  on  the  adjacent  island  and  hauling  to  where  they 
could  be  floated.  They  were  generally  towed  across  the  narrow  river 
by  a  steam-tug. 

15.  Q.  How  far  was  it  placed  from  the  city  ? 

A.  Seven  thousand  yards  from  the  nearest  point. 

16.  Q.  WThat  damage  did  it  do  to  the  city  while  under  your  direction  ? 

A.  That  gun  burst  after  the  thirty-sixth  round.  I  judge  that  three- 
fourths  of  all  the  projectiles  fired  from  that  piece  entered  the  city.  I 
did  not  put  another  gun  there. 

17.  Q.  To  what  do  you  ascribe  that  failure? 

A.  The  gun  was  fired  at  a  very  high  elevation,  which  gives  increased 
strain  upon  a  gun.  Exactly  how  much  additional  strain  the  gun  has  to 
sustain  at  an  elevation  above  the  horizontal  I  do  not  know,  but  it  is 
regarded  as  considerable. 

18.  -Q.  If  it  had  been  perfectly  level,  how  long  would  it  have  lasted? 
A.  It  ought  to  have  lasted  300  or  400  rounds;  and  I  judge  because 

the  average  endurance  of  his  guns  is  310  rounds.    I  have  always  regarded 
the  form  of  Mr.  Parrott's  large  guns  as  defective. 

19.  Q.  What  damage  do  you  think  was  done  by  the  guns  that  did  that 
firing? 

A.  The  lower  two-thirds  of  the  city,  in  the  first  place,  was  rendered 
untenable  by  the  batteries  playing  upon  it.  I  should  judge  three-fourths 
of  the  houses  in  that  portion  of  the  city  were  to  a  certain  extent  injured; 
sqine  of  them  almost  destroyed. 

20.  Q.  Do  you  think  if  you  had  used  greater  charges  of  powder  in 
those  guns  they  would  'have  been  more  effective,  if  they  had  been  able 
to  withstand  the  pressure? 

A.  They  would  not  have  been  more  effective,  so  long  as  we  reached 
the  city  with  the  charge  we  used.  The  projectiles  would  have  gone  a 
little  further,  but  there  would  not  have  been  a  very  great  increase  in 
falling. 

21.  Q.  Would  they  have  stood  a  greater  pressure  of  powder  than  you 
did  use  ? 

A.  They  would  have  stood  a  greater  pressure  of  powrder  a  few  rounds, 
but  would  not  have  stood  so  many  rounds.  I  adopted  the  plan  of  using 
Mr.  Parrott's  own  charge.  He  prescribed  a  charge  for  his  gun,  and  I 
thought  it  was  but  fair  to  use  that  charge. 

22.  Q.  Do  you  know  anything  of  the  Ames  wrought-iron  gun? 

A.  Yes,  sir ;  something  of  it.  I  witnessed  the  process  by  which  it 
was  made ;  and  I  was  president  of  a  board  of  officers  that  tested  one  of 
Ames's  7-inch  rifles  in  the  autumn  of  1864. 

23.  Q.  Could  you  have  done  any  better  on  the  city  with  one  of  those 
guns  than  you  did  with  Parrott's  ? 


42  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

A.  If  I  had  had  guns  all  as.  good  as  the  one  we  tried,  I  could  have  done 
better. 

24.  Q.  What  sort  of  a  gun  was  it  ? 

A.  This  was  a  wrought:iroii  gun,  calibre  of  7  inches,  rifled  for  a  pro- 
jectile weighing  about  or  over  100  pounds;  I  forget  what  it  was. 

25.  Q.  Do  you  know  how  the  velocity  of  the  shot  from  it  compared 
with  that  from  the  Parrott? 

A.  I  presume,  with  the  same  charges,  the  initial  velocity  would  be  the 
same. 

26.  Q.  Had  it  endurance  to  stand  a  higher  charge  of  ammunition  ? 
A.  I  think  it  had.    We  used  higher  charges  in  testing  this  gun  than 

Parrott  had  prescribed  for  his. 

27.  Q.  How  many  rounds  did  that  undergo  ? 

A.  I  believe  w^e  fired  it  713  times,  and  many  of  those  charges  were 
considerably  higher  than  Parrott  uses. 

28.  Q.  Was  it  fired  at  greater  elevation,  too  I 

A.  It  was  fired  at  greater  elevation  than  the  swamp-angel  battery. 

29.  Q.  Were  the  elevations  in  the  trials  equal? 

A.  No,  sir;  but  some  of  the  elevations  were  quite  high.  Some  between 
20  and  30  degrees,  1  believe.  We  fired  Parrott's  gun  as  a  mortar;  I 
think  it  was  nearly  40  degrees.  We  fired  Mr.  Ames's  gun  several  times 
at  high  elevation,  but  it  was  not  as  high  as  that. 

30.  Q.  You  got  Ames's  up  to  about  twice  the  amount  of  charges  ? 

A.  I  think  we  did;  yes,  sir.  Tke  effect  upon  the  gun  was  to  enlarge 
the  bore  at  the  seat  of  the  charge,  I  think  about  three-eighths  or  one- 
fourth  of  an  inch.  That  enlargement  showed  on  the  outside  of  the  gun 
in  a  little  bulge  all  around  it.  The  board  reported  favorably  of  that 
gun,  recommended  it  should  be  bored  out  to  an  8-inch  calibre  and  tried 
again.  That  was  subsequently  done,  I  understood,  under  another  board. 
I  had  nothing  to  do  with  it. 

31.  Q.  Did  you  see  any  of  those  Ames  guns  afterwards? 
A.  No,  sir ;  I  never  had  any  of  them. 

32.  Q.  Did  you  ever  ask  for  any  of  them  ? 

A.  I  had  no  command  after  that  where  I  had  occasion  to  use  heavy 
guns.  I  took  command  subsequently  in  the  south,  but  no  operations 
that  required  heavy  guns  were  going  on. 

33.  Q.  Then  you  could  not  tell  me  in  how  much  less  time  you  could 
have  accomplished  the  chief  object  on  the  city  with  the  Ames  guns  if 
you  had  had  them  in  place  of  Parrott's. 

A.  I  did  not  lay  much  stress  on  accomplishing  any  special  object  on 
the  city.  I  could  have  demolished  Fort  Sumter  sooner  if  I  had  had 
good  guns. 

34.  Q.  Suppose  you  had  had  the  Ames  gun  there,  or  something  like 
it — a  gun  you  could  have  relied  upon  for  as  much  force  as  you  pleased  ! 

A.  If  I  had  had  a  gun  that  would  have  stood  all  the  rounds  required, 
I  should  have  saved  one-third  of  the  time  in  demolishing  Fort  Suniter, 
for  it  required  a  great  deal  of  time  in  getting  up  these  heavy  guns  when 
one  of  them  burst  prematurely. 

35.  Q.  I  have  always  had  the  impression  you  were  very  much  embar- 
rassed before  Charleston  for  the  want  of  proper  ordnance.    How  was 
that,  general  ? 

A.  We  supposed  we  had  the  best,  though  I  always  supposed  a  gun 
ought  to  stand  1,000  or  1,200  rounds,  and  Parrott's  heavy  guns  stood  on 
an  average  310. 

36.  Q.  We  had  none  but  Parrott's  when  you  went  there  ? 

A.  Never  had  any  heavy  guns  but  Parrott's.    We  tried  to  study  into 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  43 

the  cause  of  this  bursting  of  guns  prematurely.  Some  officers  attributed 
it  to  one  cause  and  some  to  another.  Parrott  attributed  it  entirely  to 
the  shells  bursting  inside.  I  thought  it  was  c^ue  mostly  to  the  defective 
form  of  the  gun  in  the  large  guns.  I  do  not  want  a  better  small  gun 
than  Parrott's.  His  30-pounders  and  20-pounders  have,  as  a  general 
rule,  very  great  endurance.  I  suppose  after  getting  a  good  small  gun  he 
was  allowed  to  suppose  he  could  furnish  every  sort  of  a  gun,  and  he  had 
such  control  of  the  ordnance  department  that  they  would  take  none  but 
his.  He  applied  the  same  rules  in  getting  out  large  calibres  as  with 
small  ones. 

37.  Q.  Suppose  you  had  everything  there  of  the  right  sort  of  material 
when  you  first  made  your  demonstration  on  Charleston,  what  amount 
of  saving  of  money  would  there  have  been  ?  can  you  give  anything  near 
it? 

A.  If  I  had  had  good  guns  I  could  have  done  my  share  of  the  work 
three  weeks  sooner,  I  think.  After  that  it  was  for  the  navy  to  go  in 
according  to  agreement. 

38.  Q.  What  would  probably  have  been  the  saving  in  life  and  wounded 
if  you  had  had  guns  that  would  not  have  burst  ? 

A.  We  lost  no  men  by  the  bursting  of  guns.  Do  not  think  we  lost  a 
single  life  by  it. 

39.  Q.  Dy  you  remember  how  many  guns  were  burst  ? 
A.  Including  one  small  gun — a  30-pounder — I  burst  23. 

40.  Q.  In  what  length  of  time  I 

A.  During  the  summer  and  autumn  of  1863,  and  in  the  winter  of 
1863->64. 

41.  Q.  How  many  did  you  throw  out  of  use  besides  those  actually 
destroyed  ? 

A.  We  mounted  and  used  all  the  guns  sent  to  us  as  long  as  they  were 
serviceable.  They  either  became  unserviceable  by  bursting  open  or  by 
the  muzzle  blowing  off,  and  we  charged  them  all  as  bursted  guns,  making 
the  23.  The  30-pounder  which  is  included  in  that  number  was  tired  at 
the  city  of  Charleston  4,600  rounds  at  high  elevation. 

42.  Q.  So  you  think  that  small  guns  do  better  than  large  ones  ? 

A.  Yes,  sir ;  and  other  officers  who  have  used  them  entertain  the  same 
opinion. 

43.  Q.  Who  took  command  after  you,  general  ? 

A.  I  moved  with  the  tenth  army  corps  to  James  river  and  left  the 
command  temporarily  with  General  Hatch,  and  General  Foster  arrived 
almost  immediately  afterwards,  and  took  command. 

44.  Q.  How  many  Parrott  guns  burst  after  that  in  command  of  Hatch 
and  Foster  ? 

A.  When  I  went  back  to  the  command  of  the  department  again  in 
1865,  I  found  the  records  of  the  artillery  service  in  the  department  and 
got  them  together,  and  I  found  General  Foster  had  kept  up  the  bom- 
bardment against  Charleston  and  Sumter,  and  had  burst  27  guns,  accord- 
ing to  the  report  of  his  chief  of  artillery. 

45.  Q.  Were  any  disabled  besides  those  burst  ? 

A.  I  found  no  report  of  any  disabled  except  burst. 

46.  Q.  Were  your  operations  on  Charleston  any  way  interfered  with 
by  the  want  of  cannon  such  as  you  had  confidence  in  f 

A.  Only  by  the  delay  which  was  occasioned  by  the  bursting  of  the 
guns  in  the  demolition  of  Fort  Sumter  ? 

47.  Q.  That  was  a  great  deal,  was  it  not  ? 

A.  It  would  have  been  a  great  deal  if  the  programme  had  been  car- 
ried out,  perhaps  5  but  the  programme  was  not  carried  out  at  all  after- 
wards. 


44  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

49.  Q.  I  remember  the  country  had  an  intense  interest  fixed  upon  you 
for  a  time,  and  for  a  while  everything  was  going  on  finely  ;  but  for  some 
reason  it  was  supposed  you  were  not  able  to  proceed,  and  I  never  could 
understand  the  cause  of  it.     There  was  a  general  impression  in  the 
country  that  you  were  not  supplied  properly. 

A.  I  was  supplied  with  everything  necessary,  and  I  did  what  I  was 
sent  there  to  do. 

50.  Q.  It  was  not  your  instructions  to  do  anything  towards  the  demo- 
lition of  Charleston  ? 

A.  I  was  to  demolish  Fort  Sumter,  so  it  would  not  be  in  the  way  of 
the  navy.  The  firing  on  the  city  was  done  on  my  own  responsibility. 

51.  Q.  If  they  had  let  you  alone  would  not  you  have  taken  that  city1? 
A.  If  they  had  given  me  a  navy  I  would  have  taken  it.    I  had  not 

troops  enough  to  land  on  the  mainland. 

52.  Q.  How  many  more  troops  ought  you  to  have  had  1 

A.  In  1863  I  ought  to  have  had  10,000  more  men  to  have  made  my 
force  equal  to  Beauregard's. 

53.  Q.  That  could  have  been  easily  supplied? 

A.  The  operations  in  the  valley  of  the  Mississippi  were  pending;  then, 
and  all  the  spare  men  were  going  there,  to  Port  Hudson  and  Vicksburg 
an(I  other  points. 

54.  Q.  Could  you  with  the  Ames  gun,  like  the  one  you  fired  at  Bridge- 
port, have  reduced  all  the  enemy's  works  and  the  city  of  Charleston  in  the 
time  you  were  there? 

A.  I  do  not  think  I  can  answer  that.  We  did  not  want  any  more 
guns.  We  wanted  a  navy.  We  had  guns  enough. 

55.  Q.  Give  your  opinion  of  the  general  merits  or  defects  of  a  heavy 
wrought-iron  gun,  as  compared  with  those  made  of  cast  iron. 

A.  Well,  I  have  thought  from,  the  experiments  at  Bridgeport  that  we 
had  no  heavy  cast-iron  gun  as  good  as  Mr.  Ames's  wrougnt-iron  gun. 
Recent  trials  with  our  15-inch  gun  have  been  very  satisfactory,  and  it  is 
possible  that  gun  will  be  able  to  do  all  the  ordnance  department  claim 
for  it.  I  do  not  know. 

56.  Q.  If  it  does  that  will  it  be  any  better  than  the  Ames  gun  ? 
A.  No,  sir,  it  will  not  be  any  better. 

57.  Q.  Do  you  think  it  possible  to  produce  uniformity  of  weld  in 
wrought-iron  guns  of  large  calibre? 

A.  I  think  it  is,  by  Mr.  Ames's  process,  and  I  think  if  a  defective 
weld  does  get  into  a  gun  it  will  be  developed  in  proving  it. 

58.  Q.  Give  me  your  opinion  generally  about  the  use  of  wrought-iron 
guns  and  their  value  as  compared  wilh  cast  ones. 

A.  A  wrought-iron  gun,  in  my  opinion,  if  made  by  this  process  of 
welding  rings  together,  which  is  Mr.  Ames's  patent,  and  we  can  get  a 
gun  without  defective  welds,  would  be  one  of  the  most  valuable  guns 
we  could  have;  and  I  believe  that  a  defective  weld  would  be  developed 
in  proving  a  gun.  If  it  does  not  break  in  the  proof  charges — say  eight 
or  ten  heavy  charges — I  should  regard  the  welds  good. 

59.  Q.  That  would  be  easily  tried,  then,  would  it  not? 

A.  Yes,  sir ;  although  a  defective  weld  was  discovered  in  the  gun  we 
tried  at  Bridgeport  on  the  second  trial. 

60.  Q.  And  how  long  did  it  last? 

A.  It  fired  713  rounds  with  us,  but  I  believe  only  fired  a  few  rounds 
after  they  bored  it  out  to  enlarge  the  calibre.  It  was  heavy  enough  for 
an  8-inch  gun,  as  compared  with  the  weights  of  guns  of  that  calibre. 

61.  Q.  It  burst  after  having  been  bored  out,  did  it? 

A.  So  I  understood.    I  was  not  connected  with  the  experiments  made 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  45 

afterwards.  No  piece  of  cast  metal,  in  my  opinion,  unless  possibly  it  is 
cooled  on  the  inside,  will  make  a  good  gun  all  in  one  piece.  I  do  not 
know  but  the  cooling  inside  will  secure  a  good  gun  of  very  large  calibre 
out  of  one  piece  of  iron,  but  I  am  not  satisfied  of  it  entirely;  but  I  do 
not  believe  any  piece  of  cast  metal,  unless  it  is  cooled  on  the  inside,  can 
possibly  make  a  good  gun  of  large  calibre. 

62.  Q.  Suppose  you  had  taken  Charleston  when  you  first  went  down 
there,  what  would  have  been  tke  effect  of  it  on  the  country!    Would 
not  Savannah,  Wilmington,  and  all  the  other  southern  ports  and  places 
have  give  up  at  once?    Did  not  they  look  on  Charleston  as  the  great 
citadel  of  the  south,  on  which  everything  depended? 

A.  They  looked  upon  Charleston  as  a  very  important  place  for  block- 
ade-running. Its  military  strength  never  was  very  great,  independent 
of  its  being  used  as  a  source  of  supply  through  blockade-running  vessels. 
Wilmington  was  equally  good.  Savannah  was  used  a  little  through  the 
by-channels.  They  did  not  go  up  the  Savannah  river,  but  went  up  the 
Wilmington  river.  I  think  the  effect  upon  the  war  would  have  been  to 
shorten  it,  though  I  cannot  say  how  much.  I  should  have  regarded 
Vicksburg  as  about  the  the  most  important  capture  of  any  city  during 
the  war.  But  the  failure  to  take  Charleston  is  not  intimately  connected 
with  the  subject  of  heavy  guns.  It  opens  another  field  entirely. 

63.  Q.  Do  you  know  any  gun  superior  to  the  Ames  gun  for  strength 
and  endurance?    * 

A.  I  do  not ;  but  there  may  be  such  a  gun.  My  knowledge  of  heavy 
guns  just  now  may  not  be  up  to  the  times.  I  have  been  on  other  duty 
for  a  year,  exclusively. 

64.  Q.  But  daring  the  war  you  knew  all  about  them? 

A.  Yes,  sir ;  had  a  good  deal  to  do  with  heavy  guns  up  to  the  time  we 
tried  the'  Ames  gun.  Do  not  think  we  had  anything  as  good  as  that, 
and  the  board  expressed  that  opinion  in  their  report. 

65.  Q.  You  have  not  heard  of  any  since? 
A.  No,  sir. 

66.  Q.  Did  the  wrought-iron  gun  enlarge  more  than  the  cast-iron  or 
other  ones? 

A.  They  are  apt  to. 

67.  Q.  So  as  to  make  them  materially  larger? 

A.  They  enlarge  considerably  more  than  cast-iron,  but  they  will  stand 
a  larger  charge  without  bursting. 

68.  Q.  Then  the  enlargement  is  not  material,  is  it? 
A.  Yes,  sir;  it  becomes  so  after  a  while. 

69.  Q.  Is  there  any  injury  by  an  enlargement  of  yL,  -i,  or  1  of  an  inch 
to  the  calibre? 

A.  There  is  no  injury  in  the  accuracy  of  the  firing,  because  that  enlarge- 
ment takes  place  at  the  seat  of  the  charge,  and  not  along  the  bore. 

70.  Q.  With  the  charge  used  by  Mr.  Ames  in  his  gun  is'it  likely  to  en- 
large much ;  or  did  those  that  you  saw  enlarge  much  with  the  use  of  his 
ammunition  ? 

A.  We  did  not  use  Mr.  Ames's  ammunition. 

71.  Q.  Well,  with  the  ammunition  you  used,  was  there  much  enlarge- 
ment ? 

A.  The  enlargement  was  not  very  great  until  we  commenced  to  use 
large  charges. 

72.  Q.  Is  it  your  opinion  that  cast-iron  rifled  cannon  can  be  made  to 
stand  sufficient  charges  of  powder  to  be  effective  against  iron-clad  ves- 
sels or  against  fortifications  that  are  now  being  constructed? 

A.  I  have  not  formed  any  opinion  on  that  subject,  and  very  few  officers 
have,  I  think. 


46  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

73.  Q.  How  many  times,  in  your  opinion,  would  the  cast-iron  100- 
pounder  rifled  gun  stand  the  charge  of  quick-burning  powder,  20  pounds 
to  the  charge,  and  100-pound  shot  I 

A.  That  is  a  pretty  big  charge.  How  many  rounds  it  would  stand  is 
mere  guess.  I  do  not  know  of  any  cast-iron  gun  that  would  stand  500 
such  charges,  and  I  should  be  afraid  to  trust  them  to  stand  200. 

74.  Q.  What  is  your  opinion  about  the  necessity  of  using  rifled  cannon  I 
A.  If  the  heavy  Rodman  guns  prove  a  success,  we  want  very  few 

rifled  cannon.  If  they  wiH  not  stand  the  heavy  charges  which  the 
ordnance  department  expect  them  to  stand,  we  shall  have  to  resort  to 
rifled  cannon  to  get  the  necessary  velocity  and  weight  of  ball  to  pene- 
trate iron-clad  vessels. 

75.  Q.  That  is  an  experiment  yet  ?  • 

A.  Yes,  sir.  If  the  15-inch  gun  will  stand  100  pounds  of  powder  right 
along  through  800  or  900  rounds,  we  can  beat  off  any  iron-clad  fleet  with 
those  guns,  I  think. 

76.  Q.  That  you  do  not  know  yet  I 

A.  Only  know  that  they  have  stood  several  rounds. 

77.  Q.  Would  you  think  a  gun  weighing  20,000  pounds  capable  of  pene- 
trating the  same  thickness  of  earth,  air,  or  iron,  with  45  pounds  of  pow- 
der as  a  15-inch  gun  weighing  49,000  pounds,  with  100  pounds  of  powder, 
a  more  desirable  gun  to  obtain  for  the  service  ? 

A.  In  some  respects  it  would  be  the  most  desirable  gun  5  in  others  it 
would  not. 

78.  Q.  It  would  be  a  great  deal  cheaper  ? 

A.  It  would  be  cheaper,  and  a  more  desirable  gun  when  you  wanted 
to  punch  a  hole  through  ;  but  when  you  wanted  the  racking  effect  of  a 
large  mass  thrown  against  the  side  of  a  vessel,  I  do  not  think  this  small 
gun  would  be  as  good  as  the  big  one. 

79.  Q.  Is  not  that  a  question  with  the  English  authorities,  which  is 
the  best  effect  to  produce  ? 

A.  No  $  but  it  is  yet  a  question  with  us. 

80.  Q.  Explain  your  views  as  to  the  difference  in  value  of  light  and 
heavy  guns  capable  of  performing  the  same  amount  of  work. 

A.  The  light  guns  are  the  most  desirable,  if  they  will  do  the  kind  of 
work  you  want  done,  of  course. 

81.  Q.  Did  you  use  any  smooth-bore  guns  at  all  there  at  Charleston  ? 
A.  No,  sir  $  not  large  guns. 

82.  Q.  Why? 

A.  All  our  ranges  were  very  long.  I  used  smooth-bore  guns  at  Fort 
Pulaski.  There  we  had  only  a  mile  to  breach,  and  I  did  not  have  any 
new  rifled  guns.  I  had  our  old  42-pounder  and  32-pounder  guns  rifled 
out  to  fit  James's  projectile ;  and  then  I  had  the  8-inch  and  10-inch 
smooth-bore  columbiad ;  but  used  none  of  them  in  our  heavy  batteries 
before  Charleston,  at  all. 

83.  Q.  Did  not  use  them  as  a  matter  of  choice,  not  because  you  did 
not  have  them  ? 

A.  They  would  not  have  been  effective  at  the  distance  I  had  to  fire. 

84.  Q.  What  are  the  charges  of  powder  and  shot  used  in  rifled  guns 
above  0T^-inch,  7,  8,  9,  and  10-inch  bore,  and  do  these  charges  give  full 
velocity  to  the  shot  ? 

A.  These  charges  are  given  in  a  table  in  my  report — that  is,  the 
charges  for  Parrott  rifles. 

85.  Q.  Are  you  willing  that  what  is  said  in  that  report  shall  go  as 
part  of  your  testimony  ? 

A.  Yes,  sir ;  I  am  willing  to  take  any  or  all  this  book  as  testimony, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  47 

("Engineer  and  Artillery  Operations  against  the  Defences  of  Charleston 
Harbor,  1863.")  Here  are  the  charges  :  a  200-pounder  is  16  pounds  of 
powder  $  a  300-pounder,  which  is  a  10-inch  bore,  is  25  pounds  ;  and  that 
is  as  high  as  it  goes.  Parrott  has  only  the  8-inch  and  10-inch  above  the 
G-^L-inch  guns. 

86.  Q.  How  much  more  powder  in  each  calibre  would  it  take  to  give 
the  shot  its  greatest  velocity  ? 

A.  I  should  think  the  initial  velocity  would  increase  up  to  one-half 
more  of  the  charge,  though  there  would  be  a  good  deal  of  unburned 
powder. 

87.  Q.  Then  why  is  not  that  largest  amount  of  charge  put  in  so  as  to 
give  the  greatest  velocity  ? 

A.  The  gun  would  not  endure  it  so  long. 

88.  Q.  Then  the  gun  which  would  endure  the  more  is  so  much  better 
than  one  that  will  not  ? 

A.  Yes,  sir,  certainly ;  the  heavier  charge  the  gun  will  endure,  the 
better  the  gun  is. 

89.  Q.  Do  you  think  it  a  good  gun  that  would  not  stand  such  a  charge — 
the  heaviest  amount  of  charge  which  its  calibre  would  allow  9 

A.  It  is  a  mere  question  of  the  endurance  of  iron  as  against  the  expan- 
sive effect  of  powder.  We  may  not  be  able  to  get  any  gun  that  will 
stand  the  charge  you  ought  to  fire  to  get  the  greatest  velocity,  but  the 
gun  that  will  nearest  support  that  is  the  best. 

90.  Q.  What  gun  comes  the  nearest  that  ? 

A.  I  do  not  know  of  any  gun  stronger  than  Ames's. 

91.  Q.  Then  could  you  tell  me  what  would  be  the  comparative  differ- 
ence between  a  gun  which  would  stand  the  largest  amount  of  powder 
and  ball,  and  one  which  would  take  a  less  amount  ?    Take,  for  instance, 
the  Ames  and  Parrott  gun,  i  i  all  their  usefulness  in  the  service  ? 

A.  Well,  I  should  regard  the  gun  that  would  stand  1,000  rounds  as 
twice  as  valuable  as  one  that  would  stand  500  rounds. 

92.  Q.  Would  not  it  be  more,  because  there  is  all  the  expense  of  getting 
it  ready,  and  loss  of  time  in  getting  another  one  ? 

A.  Well,  twice  as  valuable,  at  least ;  unless  I  made  a  calculation  I 
could  not  tell  exactly  the  difference. 

93.  Q.  Are  you  familiar  with  the  mode  of  construction  of  the  Ames 
gun? 

A.  Measurably  so ;  I  saw  a  portion  of  the  process  of  making  one,  and 
understand  how  it  is  made  by  description  5  it  is  described  in  that  report 
of  mine. 

94.  Q.  What  is  the  particular  value  of  its  construction  over  a  cast-iron 
or  any  other  one? 

A.  I  understand  one  of  the  strong  points  in  favor  of  that  mode  of  con- 
struction is  that  the  strain  upon  the  metal  is  brought  lengthwise  of  the 
fibres  to  a  certain  extent. 

95.  Q.  How  are  the  fibres  formed ;  in  parallels,  or  in  transverse  sections  ? 
A.  The  outer  ring,  if  I  recollect,  is  a  hoop  all  around  the  gun.    The 

inner  portion  of  each  ring  is  a  block  of  iron  with  a  hole  punched  in  it — 
if  I  do  not  forget. 

96.  Q.  What  advantage  is  there  in  that  mode  of  formation ;  is  that 
what  gives  it  its  power  to  resist  f 

A.  The  laminad  of  the  wrought  metal  lie  transversely  to  the  axis  of  the 
gun,  in  the  inner  portion  of  each  ring. 

97.  Is  not  the  fibre  in  iron  the  result  of  extension,  as  candy  is  drawn 
out  by  the  confectioner  from  crystallized  sugar  ? 

A.  Yes,  sir. 


48  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

98.  Q.  Does  Mr.  Ames's  system  involve  initial  tension  ? 
A.  I  should  not  think  it  did. 

99.  Q.  Does  it  give  the  fibre  of  the  metal  a  transverse  direction  around 
the  gun  ? 

A.  A  portion  of  the  fibre  runs  round  the  gun  $  a  portion  of  it  lies  in 
laminae,  transverse  to  the  axis  of  the  gun. 

100.  Q.  Would  not  the  fibre  be  destroyed  by  it  after  heating  and  a  new 
crystallization  be  formed  ? 

A.  Under  continued  heating  there  is  a  new  crystallization  to  a  certain 
extent,  but  where  it  commences  and  how  rapidly  it  progresses  I  do  not 
know. 

101.  Q.  If  you  had  sections  in  the  state  of  tension,  deemed  necessary 
to  best  restrain  the  pressure  from  within  the  gun,  would  the  tension 
remain  after  the  gun  had  been  heated  to  the  welding  temperature  1 

A.  No  5  it  would  take  off  the  initial  tension. 

102.  Q.  Do  you  know  why  the  Armstrong  gun  was  fired  with  enlarg- 
ing charges  previous  to  the  last  boring  to  the  final  calibre! 

A.  I  do  not  know,  though  I  think  I  could  guess.  It  was  to  give  the 
tension. 

103.  Q.  If  you  were  before  an  enemy,  and  his  guns  would  stand  a 
third  more  powder  than  yours,  what  would  be  the  value  of  each  ? 

A.  He  could  reach  me  before  I  could  him  ;  that  is  about  it. 

104.  Q.  Could  he  not  destroy  you  before  you  could  get  ready  ? 

A.  There  would  have  to  be  some  manoeuvring  then,  I  guess,  to  get  out 
of  his  way.  However,  that  problem  cannot  be  figured  right  down  in  that 
way.  He  would  have  an  advantage  on  the  water,  undoubtedly,  and  the 
advantage  might  be  measured ;  but  on  the  land  he  would  not  have  that 
advantage.  Probably  nearly  all  the  actions  on  land  take  place  within 
the  range  of  the  weakest  ordnance  they  have.  But  an  enemy  on  the 
ocean,  having  the  longest  range,  can  lie  at  Ms  own  distance  and  fight 
entirely  beyond  the  range  of  his  adversary's  guns. 

105.  Q.  Did  you  notice  such  uniformity  in  the  manner  of  bursting 
guns  where  accidents  have  happened  under  your  direct  observation  as 
to  lead  you  to  think  there  was  a  law  governing  the  forces  acting  to  rup- 
ture them  ? 

A.  The  force  of  exploding  powder  is  applied  according  to  a  certain 
law  always,  of  course  ? 

106.  Q.  Do  you  think  the  pressure  of  the  gas  of  the  powder  is  uni- 
form at  all  times — of  course,  with  all  the  circumstances  the  same ;  is  it 
something  that  can  be  calculated  definitely  with  uniformity  $ 

A.  The  force  of  the  same  powder  fired  under  precisely  the  same  cir- 
cumstances ought  to  be,  and  I  should  think  would  be,  the  same. 

107.  Q.  Do  you  think  that,  under  the  most  favorable  circumstances  of 
lubrication  of  the  shot,  smoothness  of  the  bore,  and  time  of  ignition  of 
the  charge,  that  the  force  and  velocity  imparted  to  the  shot  is  a  fair 
evolution  of  the  amount  of  work  the  powder  is  capable  of  performing  I 

A.  I  do. 

108.  Q.  Then,  if  any  material  part  of  the  force  of  the  powder  should 
be  expended  otherwise  than  in  expelling  the  shot,  for  instance,  in  burst- 
ing the  gun,  the  shot  would  not  be  thrown  so  far,  would  it  ? 

A.  Shot  do  go  as  far  at  times,  about  as  far,  when  the  gun  bursts  as 
when  it  does  not,  and  the  forces  are  exerted  simultaneously  on  the  shot 
and  the  gun.  This  gas,  while  expelling  the  ball  is  also  bursting  the 
gun  ;  the  ball  gets  its  velocity  in  the  gun  about  the  same  time  the  gun 
reaches  that  strain  when  it  must  give  way.  There  is  no  sudden  enlarge- 
ment of  the  capacity  of  the  bore  behind  the  ball  until  the  gun  gives 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  49 

way.  If  the  gases  could  expand  the  capacity  of  the  bore  behind  the 
ball  suddenly,  then  the  shot  would  not  go  as  far  ;  but  it  does  not  do 
that.  The  gun  bursts  when  the  bore  enlarges. 

109.  Q.  Would  it  reach  its  destined  object  ? 

A.  It  will  go  just  about  as  far  and  just  about  as  straight.  That  is 
the  result  of  my  observation. 

110.  Q.  Then  only  a  portion  of  the  work  the  powder  is  capable  of 
doing  is  exerted  on  the  shot ;  the  large  amount  of  it  being  exerted  on 
the  gun. 

A.  It  is  exerted  on  the  shot,  too. 

111.  Q.  Do  you  think  a  Parrott  gun  would  burst  if  the  shot  should 
be  fastened  so  as  not  to  be  moved  from  its  home  position ;  that  is,  by 
the  direct  pressure  of  the  gas  ? 

A.  Well,  I  do  not  know.  I  should  think  his  large  guns  would ;  but  I 
never  saw  it  tried. 

112.  Q.  Would  it  not  be  nearly  all  the  work  the  powder  could  do  to 
burst  the  gun  under  such  circumstances  ? 

A.  Yes,  sir ;  I  should  think  it  would ;  but  it  will  do  just  as  much 
work  towards  throwing  the  projectile  at  the  same  time. 

113.  Q.  Do  you  believe  the  powder  capable  of  performing  twice  the 
amount  of  work  at  one  time  it  does  at  another  I 

A.  No  ;  but  I  believe  it  capable  of  performing  work  in  all  directions 
at  the  same  time.  That  is  the  nature  of  gases,  and  of  fluids  too. 

114.  Q.  Then  there  would  be  the  same  amount  of  force  exerted  in  the 
chamber  of  the  gun  whether  the  shot  went  out  or  not  ? 

A.  Yes,  sir ;  the  same  amount  of  force  developed.  That  comes  from 
the  nature  of  gases ;  the  way  gases  exert  themselves. 

115.  Q.  There  have  been  tables  of  ranges  established  for  the  Parrott 
gun,  I  believe ;  are  they  nearly  correct ! 

A.  I  think  so. 

116.  Q.  Have  you  ever  known  a  shot  to  perform  only  one-fourth  of  its 
range  when  all  the  conditions  of  loading  were  attended  to  properly,  and 
if  so,  did  the  gun  burst  at  such  time  ? 

A.  'I  do  not  recollect  any  such  case. 

117.  Q.  Then  the  powder  is  shown,  by  the  range  of  the  shot,  to  be 
nearly  uniform  in  its  action  I 

A.  Yes.  Well,  the  same  powder  would  be  under  exactly  the  same 
circumstances.  I  suppose  that  condition  applies  to  all  these  questions. 
The  varying  character  of  our  powders,  the  difference  in  barrels  from  the 
same  lot,  and  the  difference  in  portions  of  the  same  barrel,  introduces 
all  sorts  of  elements  of  uncertainty  in  our  firing.  But  I  understand 
these  questions  presuppose  that  the  powder  is  of  the  same  quality,  and 
ignited  under  the  same  conditions. 

118.  Q.  The  force  of  the  powder  being  so  nearly  all  expended  in  eject- 
ing the  shot,  there  could  not  be  enough  of  its  force  spared  from  the  ejec- 
tion and  projection  of  the  shot  to  burst  the  gun  at  the  same  time  and  at 
one  operation ;  consequently  we  must  assume  that  the  bursting  is  per- 
formed a  little  at  a  time  ? 

A.  If  you  establish  the  first  part  of  that  question  as  a  hypothesis,  I 
do  not  exactly  understand  the  condition  of  things  in  the  bottom  of  a  gun 
when  it  is  fired  to  be  explained  or  stated  in  that  question.  I  think  that 
the  work  of  bursting  and  ejecting  the  shot  from  the  gun  goes  on  at  the 
same  time,  as  my  other  answers  indicate. 

119.  Q.  And  that  when  a  shot  is  projected  to  the  extreme  extent  that 
it  can  be  thrown,  there  is  just  as  much  force  exerted  to  burst  the  gun  ? 

A.  Certainly    the  gun  is  strained  just  as  much. 
Rep.  No.  266 4 


50  EXPERIMENTS  ON  HEAVY  OEDNANCE. 

120.  Q.  What  change  have  you  noticed  in  the  structure  of  the  iron 
of  guns  half  an  inch  from  the  surface  of  the  bore,  which  have  been  fired 
no  more  than  300  rounds  and  then  burst,  and  what  in  any  gun  fired  more 
than  a  thousand  rounds  I 

A.  I  have  never  examined  that  very  closely,  so  I  have  no  intelligent 
answer  to  give  to  that.  It  belongs  more  especially  to  fabricating  ord- 
nance. 

121.  Q.  Then  you  have  never  known  test  pieces  to  be  taken  from  the 
surface  of  the  bore  of  a  gun  that  burst  ? 

A.  Not  under  my  direction ;  it  is  done,  I  know,  but  I  am  not  prepared 
to  give  an  intelligent  answer  to  that. 

122.  Q.  Do  you  think  a  Parrott  100-pounder  could  be  permanently 
enlarged  in  its  calibre  by  bursting  five  shells  at  a  time  in  the  bore  ? 

A.  Simultaneously  I 

123.  Q.  Yes,  at  one  explosion. 

A.  No,  1  do  not  believe  it  would  5  not  if  there  was  no  charge  behind. 
If  there  was  a  charge  behind  and  wedging  should  take  place,  there  might 
be  a  permanent  enlargement.  I  do  not  believe  to  explode  the  charges 
in  the  shells  would  burst  the  gun.  It  might,  though  I  should  not  think 
it  would. 

124.  Q.  Then  your  theory  is  that  w^hen  the  shell  bursts  in  the  gun,  if 
the  gun  bursts  it  is  occasioned  by  the  wedging  of  the  shell. 

A.  Yes ;  the  gun  may  be  weakened  by  being  deeply  scratched  by  frag- 
ments of  the  shells,  but  the  great  strain  on  the  gun  when  the  shell  bursts 
in  it  comes  from  wedging. 

125.  Q.  Do  you  think  a  Parrott  100-pounder  could  be  broken  in  two 
just  forward  of  the  reinforce  band  by  a  fair  blow  from  the  shot  of  another 
gun  of  the  same  kind ;  or  would  it  require  a  number  of  shots  to  break 
it? 

A.  I  should  think  it  might  be  broken  or  injured  so  that  it  would  not 
be  fit  for  any  service.  It  might  be  indented  so  as  to  reach  clear  through 
into  the  bore. 

126.  Q.  Have  you  an  idea  as  to  the  depth  of  the  indentation  I 

A.  I  think  the  gun  might  be  permanently  disabled  by  even  one  shot 
fired  against  it  at  the  chase.  It  might  require  more  than  one. 

127.  Q.  Have  you  ever  seen  an  indentation  in  the  surface  of  the  bore 
of  a  Parrott  gun  which  has  burst,  from  which  you  could  determine 
whether  the  force  with  which  the  bursting  shell  had  acted  on  the  bore 
had  been  sufficient  to  cause  the  rupture? 

A.  No,  I  never  regarded  the  bursting  of  shells  sufficient  to  burst  Par- 
rott guns.  I  have  seen  the  effect  on  the  bore  of  shells  bursting  in  the 
gun,  but  I  never  regarded  it  sufficiently  serious  to  cause  the  bursting  of 
the  gun  unless  repeated  a  great  many  times. 

128.  Q.  Do  you  think  the  Parrott  guns  would  burst  if  cast  on  the  Eod- 
man  plan  ? 

A.  I  have  always  entertained  the  belief  that  they  would  be  better  if 
cast  on  that  plan,  and  I  understood  he  did  cast  his  guns,  latterly,  on  that 
plan.  Indeed,  I  understood  it  was  a  condition  imposed  by  the  depart- 
ment that  he  should  cast  them  in  that  way,  but  I  may  be  mistaken. 

129.  Q.  Is  it  your  opinion  that  would  prevent  their  bursting  I 

A.  I  do  not  know.  I  think  it  would  improve  them,  give  them  greater 
endurance. 

130.  Q.  Will  you  explain  the  advantage  which  the  Bodman  plan  gives 
in  enabling  a  gun  to  resist  the  direct  pressure  of  the  powder  ? 

A.  It  puts  the  metal  in  that  condition  to  bring  its  strength  throughout 
the  entire  thickness  of  the  gun  into  play  when  it  is  fired  5  a  portion  of 
it  being  under  initial  compression  in  the  start. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  51 

131.  Q.  Would  a  Rodman  gun  cast  hollow  and  cooled  from  the  interior, 
or  a  solid  cast  gun  of  the  same  iron,  model,  and  weight,  be  best  able  to 
resist  the  breaking  by  unequal  expansion,  if  a  heated  rod  of  iron  should 
be  inserted  in  the  bore  ? 

A.  I  should  think  the  gun  cast  solid  and  bored  out  would  stand  the 
introduction  of  the  red-hot  rod  best. 

132.  Q.  This  tension  would  weaken  the  gun  for  resisting  the  expand- 
ing force  ? 

A.  I  think  so. 

133.  Would  it  be  possible,  in  your  opinion,  to  shrink  the  band  on  the 
Parrott  gun  with  force  enough  to  reduce  the  diameter  of  the  bore  1 

A.  I  should  not  think  it  would  be,  but  I  have  been  told  by  those 
engaged  in  making  the  guns  that  it  actually  takes  place. 
.  134.  Q.  Could  the  length  of  the  bore  be  increased  in  any  slight  degree 
by  the  shrinking  of  the  band  ? 

A.  I  should  think  not. 

135.  Q.  If  the  gun  were  made  of  India-rubber,  and  th  e  band  were  shrunk 
on,  would  it  increase  the  length  of  the  gun  ? 

A.  I  think  there  is  some  doubt  about  whether  it  would.  India-rubber 
undergoes  compression.  I  do  not  think  it  would  necessarily  increase  the 
length  to  compress  it.  It  might  a  little.  India-rubber  is  not  much  like 
cast-iron,  though  India-rubber  can  be  compressed  without  its  dimensions 
in  a  lateral  direction  undergoing  any  change.  I  should  think  in  the  case 
of  a  tube,  though  violently  compressed  that  way  by  a  band  shrinking  on 
it,  it  would  elongate  a  little. 

136.  Q.  If  the  band  was  so  placed  on  the  gun  as  to  reduce  the  diam- 
eter slightly,  and  if  it  should  increase  the  length  slightly  also,  and  the 
gun  should  then  heat  from  the  interior,  would  not  the  band  be  probably 
strong  enough  to  prevent  radial  expansion,  and  cause  the  interior  of  the 
metal  to  flow  towards  the  breech,  and  towards  the  muzzle  under  the 
band? 

A.  Yes;  that  would  be  the  tendency. 

136.  Q.  If  the  cast  iron  beneath  the  band  were  hottest  within  the  bore, 
and  had  a  gradually  reduced  temperature  towards  the  outside,  would 
not  the  expansion  of  the  inner  metal  lengthwise  have  a  tendency  to  break 
the  outside,  which  would  not  expand  so  much  ? 

A.  That  is  the  tendency. 

137.  Q.  Dp  you  not  believe  that  it  is  easier  to  restrain  the  expansion 
of  a  gun  radially  if  you  permit  it  to  expand  longitudinally? 

A.  Yes. 

138.  Q.  Dp  you  think  it  would  be  possible  to  restrain  the  expansion 
of  the  cast  iron  of  a  Parrott  gun  in  all  directions  by  any  plan  of  an 
adjusting  band? 

A.  No ;  nor  any  other  gun.    That  does  not  apply  to  Parrottfs  especially. 

139.  Q.  If  you  doubted  that  the  transverse  fracture  of  the  Parrott  gun 
was  caused  by  the  unequal  heating  alone,  would  you  believe  the  heat 
might  cause  tensions  which  would  assist  the  force  of  the  powder  to  break 
the  gun  ? 

A.  Heat  develops  forces  which  would  tend  to  break  a  gun.  It  is  the 
very  first  tendency  for  a  gun  to  break  in  two  when  fired. 

140.  Q.  If  a  strong  current  of  hot  gases  should  be  brushing  over  or 
across  the  surface  of  metal,  do  you  think  more  heat  would  be  communi- 
cated to  the  same  area  of  surface  than  would  be  if  the  heated  gas  were 
merely  pressing  against  the  surface  without  currents  for  the  same  time 
of  exposure  ? 

A.  I  do  not  know,  I  am  sure. 


52  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

141.  Q.  Is  not  the  surface  of  the  vent  liable  to  receive  more  heat  per 
square  inch  on  its  surface  according  to  the  strength  of  the  current,  and 
the  length  of  time  the  current  plays  over  it,  than  any  other  equal  surface 
of  the  bore  of  the  gun  ? 

A.  It  is  subject  to  greater  wear.  Whether  a  greater  degree  of  heat  is 
evolved  there  I  do  not  know. 

142.  Q.  If  the  metal  surrounding  the  vent  for  a  radius  of  two  inches 
should  be  heated  in  this  manner,  a  force  would  be  exerted  similar  to  that 
which  would  be  exerted  if  a  hole  four  inches  in  diameter  were  made  in 
the  gun  with  its  axis  coinciding  with  the  axis  of  the  vent,  and  a  slightly 
tapered  bolt  driven  into  it,  would  not  the  gun  be  liable  to  break  trans- 
versely at  that  point  when  the  force  of  the  powder  came  to  act  upon  it  ? 

A.  That  would  be  the  tendency. 

By  the  CHAIRMAN  pro  tern. : 

143.  Q.  Do  you  know  whose  12-inch  rifle  projectiles  were  used  against 
the  iron  targets  at  Fortress  Monroe  on  September  21  and  22,  last  year  ? 

A.  They  were  called  the  Dyer  projectile,  with  the  Taylor  sabot.  That 
is  what  we  were  informed  down  there.  I  was  on  the  board.  That  is 
what  Colonel  Baylor  told  me ;  and  Mr.  Taylor  was  there  to  superintend 
their  use. 

144.  Q.  You  saw  him  there  on  the  experimental  grounds  ? 

A.  Yes,  sir;  I  understood  from  officers  there  the  original  sabot  of 
General  Dyer  had  been  improved  upon  by  Mr.  Taylor  in  its  form  and  in 
the  composition. 

145.  Q.  Did  he  explain  to  you  the  composition  of  the  sabot  he  used  in 
the  12-inch  projectiles  ? 

A.  He  explained  the  way  it  was  attached ;  and  I  remember  I  took  a 
memorandum  of  the  different  component  parts  of  the  composition.  There 
were  copper,  tin,  and  lead  in  it,  and  he  gave  me  the  proportions  at  the 
time,  I  think,  but  I  do  not  recollect  what  they  were. 

146.  Q.  Did  the  sabot  metal  take  the  grooves  well? 
A.  Yery  well,  indeed. 

147.  Q.  And  did  the  firing  exhibit  accuracy? 
A.  Yes,  sir. 

148.  Q.  Can  you  give  any  opinion  as  to  the  value  of  the  sabot  com- 
posed of  that  metal  as  compared  with  other  kinds  of  sabots  you  have 
seen? 

A.  I  have  no  opinion  with  regard  to  the  advantage  of  that  peculiar 
kind  of  alloy  composition,  though  I  know  these  projectiles  worked  as 
well  as  if  not  better  than  any  I  ever  saw  used,  and  I  presumed  at  the 
time  it  was  in  consequence  of  having  a  very  good  sabot  on. 

149.  Q.  Will  you  look  at  the  two  diagrams,  accompanying  the  patent 
of  Taylor's  soft-metal  sabot,  and  tell  me  whether  the  sabots  which  were 
used  with  the  projectiles  at  these  experiments  were  figure  1  and  figure  2.? 

A.  Figure  1  is  a  drawing  representing  what  I  suppose  to  be  a  Dyer 
projectile,  with  the  Taylor  sabot  on,  or  resembles  the  kind  of  projectiles 
used  in  the  experimental  firing  at  Old  Point  Comfort  in  September,  1866. 
The  ordnance  officers  there  informed  me  it  was  the  Dyer  projectile  with 
the  Taylor  sabot.  The  firing  was  accurate  and  satisfactory.  Colonel 
Baylor  was  the  officer  with  whom  I  had  the  conversation. 

150.  Q.  What  advantage  or  disadvantage  do  you  think  there  is  in 
having  guns  of  different  calibres  with  different  ammunition  for  the  army 
and  navy  ? 

A.  It  is  a  disadvantage,  I  think. 

151.  Q.  Would  there  not  be  a  very  great  simplifying  of  the  arming  of 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  53 

the  two  arms  of  the  service,  and  a  very  great  mutual  advantage,  if  it  were 
possible  to  use  alternately  the  same  guns  and  the  same  ammunition  in 
the  army  and  in  the  navy  ? 

A.  It  would  be  better.  I  had  occasion  to  borrow  guns  of  the  navy  on 
Morris  Island.  They  happened  to  have  the  guns  I  wanted,  and  suited 
the  ammunition  I  had ;  and  it  was  a  very  great  convenience.  They  were 
Parrott  guns.  It  would  be  an  advantage  if  all  the  calibres  corresponded 
in  the  two  arms  of  the  service. 

152.  Q.  Do  you  know  of  any  other  cases  within  your  experience  where 
there  might  have  been  an  interchange  of  arms  or  ammunition  if  the  cali- 
bres had  been  the  same  in  the  army  and  navy  ? 

A.  Cases  of  that  kind  would  only  occur  in  joint  expeditions  like  the 
one  I  was  connected  with.  I  do  not  recollect  any  other  case. 


Extract  from  testimony  of  Brigadier  General  A.  B.  Dyer. 

JANUARY  18, 1868. 

By  Mr.  BUTLER  : 

###*### 

1.  Question.  What  is  the  amount  that  is  paid,  either  in  percentage  or 
in  gross,  as  you  may  remember,  to  General  Eodman  ? 

Answer.  I  do  not  know  that  anything  has  been  paid.     I  have  no 
knowledge  of  any  amount  having  been  paid. 

2.  Q.  As  a  royalty  on  his  gun  ? 

A.  None  at  all.    I  have  answered  that  question  in  writing  as  fully  as 
I  could. 

3.  Q.  That  may  be,  sir. 

A.  I  have  no  knowledge  whatever  of  the  matter. 

4.  Q.  Have  you  any  knowledge  whatever  that  the  price  of  guns  of  the 
Eodman  pattern  has  in  any  way  been  increased  because  of  his  royalty, 
or  because  of  any  sums  to  be  paid  on  account  of  his  patent,  directly  or 
indirectly? 

A.  I  have  understood  that  there  was  a  royalty  entering  into  the  price 
of  the  gun. 

5.  Q.  How  many  hundred  thousand  dollars'  worth,  within  bounds,  have 
you  ordered  of  the  Eodman  gun  since  you  have  been  Chief  of  Ordnance? 

A.  I  do  not  remember. 

6.  Q.  Many  hundred  thousands? 
A.  Yes. 

7.  Q.  Amounting  to  millions? 

A.  I  do  not  know  whether  amounting  to  millions  or  not. 

8.  Q.  Do  you  mean  to  say  that  in  ordering  many  hundred  thousand 
pounds,  amounting  to  millions,  perhaps,  of  the  Eodman  gun,  you  never 
inquired  as  to  whether  the  price  was  increased  by  a  royalty  or  not? 

A.  I  knew  that  the  price  was  increased  by  a  royalty. 

9.  Q.  Did  you  not  inquire  how  much? 

A.  I  had  seen  it  in  print — in  the  testimony  taken  before  the  Com- 
mittee on  the  Conduct  of  the  War.    The  price  was  one  cent  per  pound. 

10.  Q.  Did  not  you  inquire  otherwise  than  what  you  saw  in  print? 
A.  No,  I  am  not  aware  that  I  ever  did. 

11.  Q.  Then,  in  contracting  for  many  hundred  thousand  dollars'  worth 
of  ordnance,  you  made  no  inquiry  except  what  you  saw  in  the  printed 
testimony  taken  by  the  Committee  on  the  Conduct  of  the  War  as  to 
whether  the  price  was  increased  by  a  royalty  paid  to  an  officer  of  the 
ordinance  department  ? 


54  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

A.  I  never  knew  that  this  was  paid  to  an  officer  of  the  department. 

12.  Q.  Or  because  of  a  patent  given  an  officer  of  the  department  ? 
A.  I  had  understood  this,  and  I  did  not  make  any  further  inquiries; 

had  understood  several  years  ago  that  this  entered  into  and  constituted 
a  part  of  the  cost. 

13.  Q.  What  proportion  of  the  cost  of  a  piece  of  heavy  ordnance 
would  one  cent  per  pound  be  as  an  average? 

A.  Something  like  one-twelfth,  I  suppose. 

14.  Q.  What  have  you  paid  a  pound,  on  an  average,  for  the  Hodman 
guns?     Give  me  the  extreme  limits,  the  lowest  and  the  highest,  since 
April,  1861. 

A.  I  should  have  to  refer  to  my  report,  which  will  probably  show. 

15.  Q.  Can  you  give  me  approximately  the  limits  ? 

A.  No ;  I  do  not  remember  what  w^as  paid  in  the  early  part  of  the  war 
for  them.  I  can  tell  you  the  later  prices  that  have  been  paid. 

16.  Q.  In  the  early  part  of  the  war  as  low  as  six  or  eight  cents? 

A.  Yes,  I  think  probably  in  the  early  part  of  the  war  as  low  as  six  or 
eight  cents. 

17.  Q.  Now  paid  ? 

A.  I  think  about  twelve  cents. 

18.  Q.  Then  it  would  vary  from  one-sixth  to  one-twelfth  I 

A.  If  it  had  been  as  low  as  six  and  as  high  as  twelve — yes,  I  should 
think  so. 

19.  Q.  Did  you  understand  that  this  royalty  or  patent  had  been  pur- 
chased by  Mr.  Knap  ? 

A.  I  did.  . 

20.  Q.  Did  he  make  all  the  Rodman  guns  I 
A.  He  did  not. 

21.  Q.  Who  did? 

A.  They  were  made  by  Mr.  Knap;  by  the  South  Boston  foundry, 
(Alger  &  Co. ; )  by  the  Eeading  (Pa.)  foundry,  (Seyfort,  McManus  &  Co.; ) 
and  by  Mr.  Parrott. 

22.  Q.  Were  not  all  those  guns  increased  in  price  by  the  royalty? 
A.  I  have  no  doubt  of  it,  sir. 

23.  Q,  And  the  makers  had  all  to  pay  this  royalty,  which  they  added 
to  the  other  cost  of  the  gun? 

A.  I  know  nothing  whatever  of  that. 

24.  Q.  Do  you  know  of  any  arrangement  by  which  they  did  not  have  to 
pay  it? 

A.  I  know  neither  one  thing  nor  the  other  in  regard  to  that. 

25.  Q.  I  find  from  your  report  that  the  amount  paid  for  Rodman  guns 
is  $2,636,600,  up  to  June  30,  1866  ? 

A.  Yes,  sir. 

26.  Q.  Did  not  you  know  Mr.  Rodman  was  interested  one-half  in  that 
royalty  ? 

A.  I  had  no  other  knowledge  than  from  hearsay  j  I  believed  it. 

27.  Q.  That  he  had  one-half? 
A.  I  believed  he  had  one-half. 

28.  Q.  Estimating  the  royalty  at  an  average  of  one-tenth  the  cost,  the 
whole  amount  of  royalty  paid  on  those  guns  would  be  $263,660.    That 
was  so,  was  it  not? 

A.  You  made  the  calculation  ? 

29.  Q.  Will  you  not  see  if  I  am  right  ? 
A.  I  believe  so. 

30.  Q.  This  is  up  to  June  30,  1866.    How  many  of  those  guns  have 
been  purchased  since? 


EXPERIMENTS    ON    HEAVY    ORDNANCE.  55 

A.  I  do  not  remember,  sir. 

31.  Q.  Are  they  still  being  purchased? 
A.  They  are  not. 

32.  Q.  When  did  it  cease? 

A.  I  think  no  orders  have  been  given. 

33.  Q.  When  did  they  cease  being  purchased?    Giving  orders  might 
be  one  thing,  and  purchasing  another.    They  might  be  received  in  ful- 
filment of  old  orders  ? 

A.  I  think  the  last  deliveries  were  made  somewhere  about  a  year 
ago — a  little  more  or  a  little  less — a  little  less,  I  think. 

34.  Q.  I  find  in  the  last  report  of  the  Secretary  of  War  the  following : 


A  board  of  engineer,  ordnance,  and  artillery  officers,  specially  appointed  to  consider  this 

the  calibre  of  13,  15, 


A  board  ot  engineer,  ordnance,  and  artillery  officers,  specially  appoi 
subject  of  arming  the  permanent  forts,  reported  the  1,915  pieces  of  th 
and  20  inches  for  smooth-bores,  and  of  10  and  12  inches  for  rifles,  were  required  for  the  per- 
manent fortifications,  and  should  be  provided,  and  their  report  was  approved  by  the  Secre- 
tary of  War.  None  of  these  guns  have  yet  been  provided.  There  are  no  orders  or  contracts 
existing  for  heavy  cannon.  This  stoppage  of  the  procurement  of  heavy  cannon  has  been 
mainly  occasioned  by  "persistent  efforts  for  some  time  past  by  ignorant  or  designing  persons 
to  destroy  public  confidence  in  the  heavy  guns  which  have  been  provided  for  the  ordnance 
departments  of  the  army  and  navy." 

This*language,  "persistent  efforts  for  some  time  past  by  ignorant  or 
designing  persons  to  destroy  public  confidence  in  the  heavy  guns  which 
have  been  provided  for  the  ordnance  departments  of  the  army  and  navy," 
is  quoted  by  the  Secretary  of  War  from  the  report  of  the  Chief  of  Ord- 
nance? 

A.  Yes. 

35.  Q.  To  whom,  sir,  did  you  refer  in  that  report? 

A.  I  referred  to  the  articles  which  were  published  in  the  newspapers, 
as  I  state,  from  time  to  time.  I  should  like  to  read  that  portion  of  my 
report. 

36.  Q.  We  have  not  been  able  to  get  a  copy.    That  is  taken  from  your 
report,  is  it  not? 

A.  That  is  from  my  report. 

37.  Q.  When  you  say,  in  your  report,  "persistent  efforts"  have  been 
made  ufor  some  time  past  by  ignorant  or  designing  persons  to  destroy 
public  confidence  in  the  heavy  guns  which  have  been  provided  for  the 
ordnance  departments  of  the  army  and  navy,"  you  refer  to  articles  which 
appeared  in  the  newspapers? 

A.  Yes,  sir;  and  to  specimens  of  iron  castings  which  are  exposed 
here  in  the  old  hall  of  representatives. 

38.  Q.  To  anything  else? 

A.  I  am  not  aware  that  I  referred  to  anything  else ;  do  not  remember 
that  I  did ;  but  those  I  mainly  referred  to. 

39.  Q.  Did  you  stop  the  business  of  the  ordnance  department  in  arm- 
ing the  fortifications  because  of  articles  in  newspapers,  and  because  of 
the  exposure  of  the  iron  castings  in  the  old  hall  of  representatives  in  the 
Capitol? 

A.  I  did  not  stop  on  that  account  at  all.  The  engineers,  or  the  chief 
engineer,  asked  for  certain  heavy  guns  about  a  year  or  more  ago.  Some 
of  those  guns  were  guns  which  had  not  been  adopted,  were  not  of  the 
models  that  had  been  adopted  for  the  arming  of  the  forts,  and  I,  upon 
consulting  with  him,  asked  that  a  board  of  officers  might  be  appointed — 
engineer,  artillery,  and  ordnance  officers — for  the  purpose  of  considering 
the  question  of  the  armament  of  the  forts  and  determining  what  guns 
were  required ;  and  I  stopped  procuring  guns,  or  declined  to  give  any 
orders  for  guns,  until  this  board  had  reported  and  their  report  had  been 
approved  by  the  Secretary  of  War  and  the  guns  ordered. 


56  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

40.  Q.  Is  that  the  "board  of  engineer,  ordnance,  and  artillery  officers 
specially  appointed  to  consider  the  subject,"  referred  to  here? 

A.  That  is  the  board  referred  to  there. 

41.  Q.  Do  I  now  understand  you  to  say  you  did  not  stop  until  a  board 
was  ordered  and  they  had  recommended,  and  their  recommendation  had 
been  approved  by  the  Secretary  of  War?    Hew  do  you  explain,  then, 
that  immediately  following  you  say:  "This  stoppage  of  the  procurement 
of  heavy  cannon  has  been  mainly  occasioned  by  i  persistent  efforts  for 
some  time  past  by  ignorant  or  designing  persons  to  destroy  public  con- 
fidence in  the  heavy  guns  which  have  been  provided  for  the  ordnance 

. departments  of  the  army  and  navy?'" 

A.  "This  stoppage  of  the  procurement ;n  I  am  not  aware  that  I  said 
that. 

42.  Q.  "By  persistent  efforts?" 

A.  I  am  not  aware  that  I  ever  said  it. 

43.  Q.  Have  you  received  your  report  in  print? 
A.  Yes,  sir. 

44.  Q.  I  pass  from  this,  then,  till  I  can  get  your  report. 

#  #  *  *  '#  *  * 

45.  Q.  To  return,  now,  to  this  question  of  heavy  ordnance :  Is  there 
any  authority  for  saying  that  the  arming  of  the  forts  has  been  stopped 
mainly  because  of  these  publications  in  the  newspapers  and  the  exhibi- 
tion of  these  castings  in  the  old  house  chamber? 

A.  I  am  not  aware  that  I  have  said  it. 

46.  Q.   That  is  not  the  question — whether  you  have  said  it.      The 
question  is,  whether  it  is  a  fact? 

A.  No.    I  do  not  know  that  it  is  a  fact. 

47.  Q.  Then  there  is  no  authority  for  saying  that? 
A.  May  I  ask  whether  you  supposed  I  had  said  so? 

48.  Q.  I  supposed  so  for  this  reason 

A.  That  does  not  appear  to  be  in  quotation  marks,  and  what  purports 
to  come  from  my  report. 

49.  Q.  I  want  to  ascertain  if  it  is  truje,  being  said  by  anybody  else ; 
because  it  is  put  forward  that  ignorant  and  designing  persons  have 
stopped  the  arming  of  the  forts;  and,  if  it  is  true,  it  is  time  those 
persons  got  out  of  the  way  and  the  armament  of  the  forts  went  on. 
Somebody  said  it,  evidently ;  and  the  statement  is  sent  to  us  for  our 
information  by  Congress.    Now,  I  think  it  is  fair  for  you  to  say  that  you 
have  not  said  it.    I  have  now  here  your  report ;  all  you  have  said  is  this : 

Persistent  efforts  have  been  made,  for  some  time  past,  by  ignorant  and  designing  persons, 
to  destroy  public  confidence  in  the  heavy  guns  which  have  been  provided  for  the  ordnance 
departments  of  the  army  and  navy. 

Iron  castings,  placarded  as  representing  the  condition  of  the  metal  in  our  heavy  guns, 
have  been  placed  in  conspicuous  public  places,  and  publications  have  appeared  from  time 
to  time,  in  prominent  journals,  asserting  that  these  guns  were  worthless,  that  they  could 
only  be  fired  with  very  light  charges  of  powder,  and  that  they  would  burst  if  fired  a  few- 
times  rapidly. 

But  you  nowhere  say  here  that  you  have  stopped  on  that  account  ? 
A.  I  told  you  I  was  not  aware  of  saying  it. 

50.  Q.  At  any  rate,  you  are  certain  you  never  did? 

A.  I  am  not  aware  that  I  ever  did  on  that  account.  I  do  not  know 
what  the  Secretary  of  War  may  have  done. 

51.  Q.  He  could  not  have  done  anything  of  that  sort  without  your 
knowledge — without  its  coming  through  you? 

A.  He  gave  me  an  order,  last  spring,  to  procure  no  more  heavy  guns 
without  his  further  authority. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  57 

52.  Q.  Did  you  understand  that  order  to  be  in  consequence  of  a  reso- 
lution from  this  committee1? 

A.  I  believe  that  it  was  in  consequence  of  it. 

Extract  from  the  statement  of  General  Dyer,  February  5,  1868 : 

It  is  true,  as  stated  by  Mr.  Wall  in  his  testimony,  that  some  Rodman  guns  have  been 
accepted  and  paid  for  before  being  fired ;  but  no  gun  has  been  accepted  and  paid  for  which 
did  not  fulfil  all  the  conditions  required  by  the  contract,  and  it  is  confidently  believed  that 
no  better  guns  have  been  furnished  the  government  than  are  all  of  the  heavy  guns  which  have 
been  procured  since  I  came  into  the  bureau. 

The  ordnance  department,  through  its  constructor  of  ordnance,  determines  the  kind  of 
metal  which  shall  be  used,  and  fixes  the  limits  of  tenacity,  density,  and  initial  strain,  and 
the  character  of  the  fracture  of  the  metal.  Specimens  have  been  taken  from  every  gun,  and 
no  gun  has  been  accepted  the  metal  of  which  had  not  been  prouounce^by  the  constructor  of 
ordnance  to  be  entirely  satisfactory.  It  is  believed  that  a  larger  proportion  of  guns  have 
been  condemned  under  the  rigid  system  of  tests  which  have  been  established  by  the  depart- 
ment than  were  formerly  condemned  when  the  guns  were  subjected  to  a  severe  powder  proof. 
To  the  best  of  my  recollection  and  belief  every  Rodman  gun  made  for  the  ordnance  depart- 
ment at  the  Fort  Pitt  foundry,  Reading  foundry,  and  the  West  Point  foundry,  has  been  fired 
three  times  at  the  foundries,  and  not  one  has  failed  under  the  powder  proof.  As  there  was 
no  suitable  proving  ground  at  South  Boston  foundry,  the  15-inch  Rodman  guns  which  were 
made  there,  and  which  are  known  to  be  equal  to  the  very  best  guns  of  the  kind  which  have 
been  made,  were  not  subjected  to  powder  proof  at  the  foundry,  nor  was  it  considered  neces- 
sary ;  and  as  the  founder  was  held  responsible  for  the  quality  of  the  metal,  as  determined  by 
tests  prescribed  by  the  department  for  the  soundness  of  casting  and  for  the  correctness  of 
the  dimensions  of  the  finished  gun,  and  not  for  the  result  of  the  tiring,  the  tiring  was  deferred 
until  the  guns  should  be  mounted  in  the  forts.  Not  one  15-inch  army  gun  has  ever  burst, 
and  some  of  them  have  been  fired  with  twice  the  quantity  prescribed  for  the  proof  of  such 
guns.  Oue  gun,  taken  without  selection  from  those  made  at  South  Boston  foundry,  and  not 
before  proved  by  firing,  has  been  fired  more  than  250  times,  upwards  of  130  rounds  being 
with  100  pounds  of  powder  and  solid  shot. 

I  never  directed  Mr.  J.  C.  Wall  not  to  prepare  copies  of  the  inspection  reports  of  cannon 
for  j'our  committee.  I  always  intended  to  furnish  them,  and,  as  far  as  I  could,  all  other 
iuformation  which  was  called  for  by  the  committee,  as  is  well' known  to  General  Maynadier, 
Colonel  Tread  well,  and  Major  McGinness,  officers  on  duty  in  the  bureau,  and  to  Mr.  Keller, 
Mr.  McNally,  Mr.  Williams,  and  the  other  clerks  in  the  bureau,  who  have  been  employed 
under  their  direction  in  preparing  the  information  called  for  by  the  committee.  I  am  very 
confident  that  all  of  these  gentlemen  will  testify  that  my  instructions  have  been  to  prepare 
full,  complete,  and  true  answers  to  all  the  questions  asked  by  the  committee. 


WASHINGTON,  D.  C.,  January  25, 1868. 

Professor,  E.  "N.  HORSFORD,  of  Cambridge,  Massachusetts,  sworn  and 
examined : 

By  Mr.  BUTLER  : 

1.  Q.  What  is  your  profession  or  business  occupation? 

A.  I  have  been  a  professor  in  Harvard  College,  until  within  two  or 
three  years,  for  the  previous  sixteen  years. 

2.  Q.  Have  you  had  such  experience  as  would  lead  you  to  have  a 
knowledge  of  gunpowder  and  its  effects  on  iron  ? 

A.  I  have  made  some  experiments  with  a  view  of  determining  the  tena- 
city of  iron  when  subjected  to  the  pressure  of  burning  gunpowder.  Shall 
I  go  on  to  state  the  experiments? 

3.  Q.  You  may  do  so  briefly. 

A.  I  prepared  short  barrels  by  cutting  off  sections  of  Sharpens  rifle 
barrels,  and  fitted  them  with  screw-thread  plugs  at  each  end  of  these 
short  barrels,  as  a  preparatory  step  to  my  experiments.  The  plugs  were 
fitted  as  male  screws,  with  counter-sunk  shoulders,  so  that  with  the  aid 
of  a  wrench  and  vice  I  could  bring  the  plugs  home  to  the  face  of  the  end 
of  the  barrel,  there  being  an  inch  in  length  of  the  interior  of  my  short 
cylinder  for  gunpowder.  In  one  of  the  cylinders  I  placed  (the  cavity 


58  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

being  an  inch  in  length)  half  an  inch  of  loose  rifle  powder ;  that  is,  half 
filled  the  cavity.  In  another  I  quite  filled  the  cavity.  In  a  third  I  pat 
in  gunpowder  compressed  in  the  cylinder,  two  volumes  in  one.  When 
all  the  plugs  were  driven  home,  I  threw  the  three  cylinders  into  the  fire. 
After  an  interval  of  a  few  minutes,  one  of  the  cylinders  gave  a  report ; 
and  a  little  later,  another  gave  a  report ;  and  there  was  no  further  report — 
that  is,  one  of  them  did  not  give  any  report.  I  took  these  cylinders  from 
the  factory  to  my  laboratory,  took  out  the  plugs  and  found  only  sulphide 
of  iron  (a  compound  of  sulphur  and  iron)  coating  the  interior  of  each 
cylinder  up  to  the  point  where  the  plug  and  the  cylinder  fitted  to  each 
other.  From  that  point,  out  along  the  line  of  the  screw-thread,  there 
was  in  every  case  a  channel,  making  the  screw-thread  thereafter  fit 
loosely.  The  surface  of  this  channel  (it  being  understood  that  the  male 
and  female  screws  originally  fitted  with  very  great  precision)  was  coated 
with  a  compound  of  sulphur  and  iron.  I  found  this  to  be  true  in  all  of 
the  cases,  the  channel  deeper  (more  of  the  metal  having  been  removed) 
in  the  case  of  the  compressed  gunpowder  than  in  the  case  of  either  of 
the  other  two.  I  repeated  these  experiments  in  my  laboratory,  suspend- 
ing the  cylinder  immediately  after  the  explosion  in  water.  Under  such 
circumstances,  the  surface  of  the  cylinder  was  immediately  coated  with 
myriads  of  minute  bubbles.  I  then  suspended  the  same  cylinder,  after 
another  experiment,  in  a  solution  of  lime  water,  and  found  that,  from  each 
of  these  points  where  the  bubbles  had  before  appeared,  a  stream  of  fine 
white  powder  descended  to  the  bottom  of  the  vessel  containing  the  lime 
water.  This  was  proof  that  carbonic  acid  came  from  the  pores  of  the 
metal.  I  found  the  exterior  surface  of  the  iron  also  to  contain  sulphur 
in  combination  with  the  iron.  I  found  in  an  experiment  with  a  piece  of 
firing  apparatus,  devised  by  Professor  Treadwell,  where  gunpowder  was 
exploded  under  pressure,  that  the  sulphur  came  through  the  iron  and 
appeared  at  the  surface,  as  in  my  experiments  with  the  short  barrels. 
From  these  experiments,  as  well  as  from  the  fact,  familiar  to  all  artil- 
lerists, that  the  vent  of  a  cannon  constantly  increases  in  diameter  under 
firing,  I  drew  the  conclusion  that  the  sulphur  of  the  gunpowder  under 
pressure  and  under  the  influence  of  heat,  in  a  degree  leaves  the  saltpetre 
and  the  charcoal  of  the  gunpowder,  and  enters  into  combination  with  the 
iron,  forming  a  compound  at  the  surface  of  the  iron  eminently  fusible, 
which,  in  the  current  of  gases  escaping  through  the  vent-hole,  or  wher- 
ever there  is  a  current  of  gas  at  the  instant  of  the  combination  of  the 
sulphur  with  the  iron,  strips  this  molten  sulphide  of  iron  off,  enlarging 
the  vent. 

4.  Q.  Did  these  various  experiments  which  you  have  described  lead  you 
to  an  opinion  as  to  the  cause  of  the  burning  out  of  the  iron  in  the  bottom 
of  the  bore  of  cannon,  as  well  as  at  the  vent? 

A.  It  led  me  to  form  an  opinion  as  to  the  cause  of  the  cavity  which 
has  been  described  to  me  as  having  been  formed  in  some  wrought-iron 
guns  which  have  been  subjected  to  experiment  within  the  last  three  or 
four  years — guns  made  by  Mr.  Ames. 

o.  Q.  Was  the  cause  of  the  formation  of  that  cavity  the  same  as  of  the 
enlargement  of  the  vent  of  the  guns? 

A.  It  is  well  known  that  if  gunpowder  be  subjected  to  heat  under 
pressure — even  without  pressure — the  sulphur  may  be  all  distilled  from 
the  saltpetre  and  the  charcoal,  leaving  the  saltpetre  and  charcoal  quite 
pure.  I  conceive  that  under  pressure,  in  the  experiments  which  I  made, 
the  sulphur  was  distilled  in  part  without  entering  into  combination  to 
form  sulphuric  or  sulphurous  acids.  In  the  case  of  the  cannon,  to  which 
the  question  refers,  I  conceive,  as  a  resultant  of  the  forces  brought  into 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  59 

play,  there  would  be,  at  the  instant  of  the  explosion  of  the  cartridge, 
along  the  axis  of  the  gun  and  towards  the  cascable,  something  like  a  jet 
of  gaseous  sulphur,  which,  striking  the  metal,  would  act  to  accomplish 
the  same  effect  that  is  produced  in  the  vent;  that  is,  a  stream  of  sulphur 
vapor,  playing  upon  a  surface  of  iron,  forms  a  compound  the  instant  the 
sulphur  strikes  the  metal ;  which  compound,  being  fusible  at  a  low  tem- 
perature, is  stripped  from  the  surface  as  fast  as  formed,  and  so  long  as 
the  stream  is  kept  up.  This  jet  would  excavate  a  hole  in  the  direction 
of  the  axis.  This  action  would  be  more  'energetic  at  the  commencement 
of  the  explosion  of  the  gunpowder  than  after  the  ball  has  left  its  seat — 
at  any  rate,  after  some  considerable  expansion  of  the  products  of  com- 
bustion has  taken  place. 

6.  Q.  Would  increasing  the  pressure  of  the  powder  increase  its  effect 
in  producing  this  result? 

A.  The  increase  in  pressure,  retarding  the  escape,  and  so  keeping  the 
sulphur  there  longer,  to  produce  its  effect,  would  accomplish  that  end. 

7.  Q.  What  is  the  difference  in  the  bursting  strain  on  a  cannon  charged 
with  powder  giving  a  pressure,  say,  of  87,000  pounds  to  the  inch,  and  of 
powder  giving  but  35,000  pounds,  pressure  ? 

A.  The  ratio  is  as  the  square.  If  35  gave  you  a  pressure  of  1,  70 
would  give  you  a  pressure  of  4 ;  87  would  be  somewhere  about  5. 

8.  Q.  So  the  pressure  in  the  first  case,  with  powder  exerting  a  pressure 
of  87,000  pounds  to  the  inch,  would  be  about  five  times  as  great,  you  say, 
as  of  powder  with  a  pressure  of  35,000  pounds  ? 

A.  Yes,  sir ;  about  that. 

9.  Q.  Having  two  guns  of  equal  calibre,  firing  equal  weights  of  powder, 
one  of  them  being  observed  to  be  excavated  at  the  bottom  of  the  bore,  in 
form  of  a  comparatively  slender  tube  or  cylinder — a  long  irregular  cylin- 
drical cavity — to  what  should  that  difference  in  the  effect  be  ascribed? 

A.  To  the  greater  strength  of  the  gunpowder,  inasmuch  as  a  more 
powerful  jet  of  sulphur  would  be  brought  to  play  upon  the  bottom  of  the 
chamber  in  the  line  of  the  axis  than  would  be  with  a  powder  of  less 
strength. 


WASHINGTON,  D.  C.,  February  20, 1868. 
ISAAC  FRENCH  sworn  and  examined. 
By  the  CHAIRMAN  : 

1.  Q.  Please  give  your  name  in  full? 
A.  Isaac  French. 

2.  Q.  Give  your  age,  residence,  and  occupation  ? 

A.  I  am  53  years  of  age ;  I  reside  in  Salisbury,  Connecticut,  and  I  am 
a  blacksmith  or  hammerman  by  trade. 

3.  Q.  Are  you  familiar  with  the  working  of  iron? 
A.  I  am. 

4.  Q.  How  long  have  you  been  engaged  in  that  business  ? 
A.  Nearly  40  years. 

5.  Q.  Do  vou  know  Mr.  Horatio  Ames  ? 
A.  I  do. 

6.  Q.  Have  you  been  in  his  employ  at  any  time? 
A.  I  have  worked  for  him  about  30  years. 

7.  Q.  In  what  capacity  ? 

A.  As  a  blacksmith,  hammerman,  or  heater,  and  other  things. 

8.  Q.  Were  you  in  his  employ  at  the  time  he  made  the  11 100-pounder 
guns  for  the  government  ? 


60  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  I  was. 

9.  Q.  Were  those  guns  made  under  your  immediate  personal  inspec- 
tion If 

A.  Yes. 

10.  Q.  During  all  the  different  stages  of  their  manufacture  f 

A.  Yes ;  I  did  a  good  share  of  the  work  myself.  It  was  all  done  under 
my  notice. 

11.  Q.  Will  you  state  briefly  the  manner  in  which  the  guns  were  manu- 
factured, beginning  with  the  mode  of  making  each  ring,  and  then  the 
putting  the  rings  together  and  forming  the  gun  ? 

A.  In  the  first  place  the  iron  is  puddled ;  that  is,  put  into  a  furnace 
and  melted,  and  then  it  is  stirred  and  worked  in  a  manner  similar  to  the 
churning  of  butter,  until  it  finally  can  be  gathered  into  a  ball,  when  it 
is  taken  out  in  the  form  of  a  large  ball  and  put  under  a  hammer  and 
beaten  into  plates  about  four  or  five  inches  wide  and  18  inches  long. 
Then  we  put  three  or  four  of  them  together  and  draw  them  out  into  a 
bar  about  five  and  a  half  inches  wide  and  three  to  three  and  a  half  feet 
long.  Then  we  cut  these  into  three  pieces  and  pile  one  piece  upon  the 
top  of  the  other.  Then  we  draw  them  out  into  what  we  call  a  slot, 
about  two  feet  and  a  half  long  and  eight  inches  wide.  Then  we  take 
them  to  the  hammer,  and  pile  them  up  on  what  we  call  a  porter-bar, 
when  they  are  heated  and  drawn  out  into  bars  for  rings,  six  inches 
square.  That  is  one  kind  of  ring.  There  are  three  or  four  different 
kinds.  But  that  is  the  process  and  way  of  working  the  iron.  Then  the 
ends  are  cut  off,  and  they  are  put  into  a  furnace  and  heated  and  bent 
around  into  a  ring.  They  are  then  taken  to  a  blacksmith's  fire  and 
welded  together ;  then  to  the  machine  shop,  and  the  inside  is  bored  out 
to  ten  inches  in  diameter  and  so  as  to  leave  them  perfectly  smooth  on 
the  inside.  The  face  is  also  turned  off  smooth.  That  is  the  process  of 
making  the  middle  ring  of  the  cylinder  of  the  gun.  The  iron  for  the 
inside  ring  is  made  in  the  same  way  and  put  together  in  the  same  way, 
only  the  ring  is  larger,  being  drawn  8  by  10  inches.  Then  they  are 
slotted  off  and  a  hole  four  inches  in  diameter  is  bored  through  them. 
They  are  then  put  on  a  mandrel  or  arbor  and  turned  off  so  as  to  be  10 
inches  in  diameter.  Then  they  are  nicely  fitted  into  this  other  ring  that 
I  have  described. 

For  the  cylinder  of  the  gun  we  have  another  ring  still,  outside  of  this, 
six  inches  by  three.  That  is  shrunk  on  to  the  other  two.  That  forms 
the  rings  5  and  that  is  all  I  can  say  about  that.  There  were  three  rings 
thus,  one  inside  of  the  other.  The  middle  ring,  which  is  ten  inches  in 
diameter,  projects  about  five-eighths  of  an  inch  from  the  other  on  the 
side  that  goes  on  to  the  gun.  The  object  of  the  projection  is  to  have  it 
strike  in  the  centre  of  the  weld,  the  centre  of  the  gun,  first. 

We  have  what  we  call  a  porter  bar,  and  on  the  end  of  this  porter  bar 
we  form  a  lump  for  the  breech,  about  15  inches  in  diameter.  Then  we 
weld  a  ring  around  that,  nine  inches  by  three  and  a  half,  and  another 
we  have  a  horizontal  hammer,  by  which  we  upset  this  and  make  it  square 
ring  around  that,  three  by  six.  That  forms  the  breech  of  the  gun.  Then 
on  the  end,  or  a  little  oval.  Then  that  is  heated  in  one  furnace  and  the 
ring  in  another.  Then  we  fetch  the  gun  out  of  one  of  the  furnaces  by 
this  porter  bar,  and  place  it  in  a  large  groove,  under  a  big  steam  hammer. 
We  fetch  the  ring  out  of  another  furnace  with  a  large  pair  of  tongs  and 
place  it  right  against  the  end  of  the  gun.  Then  this  horizontal  hammer 
which  I  have  spoken  of  strikes  against  it  and  butts  it  up  to  weld  it  on. 
There  is  a  blocking  behind  the  porter-bar  that  holds  it  fast,  and  keeps 
it  from  going  back.  Thus  we  keep  putting  on  rings  until  the  gun  is  long 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  61 

enough  ;  but  when  we  get  past  the  cylinder  of  the  gun  we  have  only  two 
rings. 

12.  Q.  The  strength  of  the  gun  depends  upon  the  perfection  of  the 
welds  ? 

A.  Yes,  of  course. 

13.  Q.  From  your  experience  in  making  these  guns,  is  it  your  opinion 
that,  with  proper  care  you  can  produce  reliable  and  perfect  welds  I 

A.  Yes,  we  can,  just  as  well  as  in  any  other  way  in  the  world. 

14.  Q.  When  the  weld  is  properly  made,  is  perfect,  is  there  any  weak- 
ness at  the  welding  point  ? 

A.  I  do  not  see  why  there  should  be  any  more  than  at  any  other  part 
of  the  gun. 

15.  Q.  Is  it  as  strong  there  as  at  any  other  portion  of  the  gun? 
A.  I  do  not  see  why  it  is  not. 

16.  Q.  Did  you  have  any  failure  to  make  the  welds,  during  your  expe- 
rience ? 

A.  No,  not  on  the  guns  that  I  made. 

17.  Q.  Did  Mr.  Anies,  in  making  any  guns,  fail  in  making  a  weld  at 
any  time  ? 

A.  We  tried  various  experiments,  and  sometimes  the  welds  were  not 
perfect. 

18.  Q.  But  after  the  system  was  perfected  you  think  the  welds  were 
such  as  could  be  depended  upon  ? 

A.  I  think  the  eleven  guns  were  perfect  welds,  and  were  as  solid  there 
as  any  where. 

19.  Q.  And  you  say  you  saw  those  guns  during  every  step  in  their 
manufacture,  so  that  you  have  perfect  knowledge  of  them? 

A.  Yes ;  I  saw  the  iron  from  the  pig  until  they  were  finished. 

20.  Q.  Are  you  confident  there  was  no  defect,  owing  to  carelessness  ? 
A.  I  took  every  pains  possible,  and  saw  every  ring  put  on. 

21.  Q.  What  was  the  character  of  the  iron  used  ? 

A.  I  think  it  was  the  best  iron  I  have  ever  worked — Salisbury  iron ;  I 
never  worked  any  that  would  stand  the  heat  as  well. 

22.  Q.  Is  it  superior  in  certain  qualities  ? 

A.  Yes;  some  iron  when  a  little  over-heated  has  its  welding  power 
destroyed.  But  the  Salisbury  iron  is  not  so  5  and  if  hammered  a  little  it 
can  be  brought  back  to  its  original  nature. 

23.  Q.  Have  you  any  personal  interest  in  this  claim  of  Mr.  Ames? 

A.  I  have  not  any  more  than  my  daily  wages.  I  have  worked  30  years 
for  Mr.  Ames,  and  he  has  never  given  me  any  bribes. 

24.  Q.  Then  you  have  not  now  any  interest  in  it  ? 

A.  No,  only  if  he  makes  guns  and  I  work  for  him,  he  will  pay  me. 


WASHINGTON,  D.  C.,  February  20, 1868. 
Mr.  JAMES  WILSON  sworn  and  examined. 
By  the  CHAIRMAN  : 

1.  Q.  Please  give  your  name  and  residence. 

A.  My  name  is  James  Wilson;  I  reside  in  Washington. 

2.  Q.  What  is  your  occupation  ? 

A.  Foreman  and  forger,  at  present,  at  the  Washington  navy  yard. 

3.  Q.  Do  you  know  anything  about  these  wrought-iron  guns  which 
Mr.  Ames  made  for  the  Navy  Department  ? 

A.  No. 


62  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

4.  Q.  Have  you  ever  seen  them  made? 
A.  No. 

5.  Q.  Are  welds,  when  perfectly  made,  as  strong  as  any  other  part  of 
the  iron  f 

A.  Yes  ;  I  think  they  are  quite  as  strong. 

6.  Q.  What  is  your  opinion  about  the  possibility  of  making  perfect 
welds  in  large  masses  of  iron,  if  you  have  suitable  tools  and  furnaces  ? 

A.  I  think  you  can  do  it  and  make  them  perfect. 

7.  Q.  You  have  heard  the  system  of  manufacture  described  here  of 
Mr.  Ames's  guns  ? 

A.  Yes. 

8.  Q.  Will  you  state  if  you  have  any  doubt  that  the  welds  could  be 
made  perfectly  by  that  system  ? 

A.  I  have  no  doubt  in  the  world ;  I  believe  it  can  be  done. 

9.  Q.  Then  you  think  there  is  no  reason  why  large  masses  of  iron 
should  oxidize  so  as  to  prevent  welding,  if  only  skilfully  and  properly 
manipulated  ? 

A.  None  in  the  world. 

10.  Q.  Will  not  large  masses  of  certain  iron  be  longer  in  oxidizing 
than  smaller  quantities,  owing  to  the  greater  amount  of  the  heat  ? 

A.  No  ;  I  do  not  think  they  would. 

11.  Q.  Do  you  think  that  would  be  in  proportion  to  the  surface  pre- 
sented 1 

A.  Yes,  I  do  not  see  any  difference  in  that  respect  between  a  large 
and  a  small  piece. 


WASHINGTON,  D.  0.,  February  20, 1868. 
WILLIAM  W.  BRADLEY  sworn  and  examined. 
By  the  CHAIRMAN  : 

1.  Q.  Please  give  your  name,  residence  and  occupation. 

A.  My  name  is  William  W.  Bradley ;  I  reside  in  Washington,  I  am  at 
the  present  time  clerk  in  the  ordnance  department ;  I  am  a  machinist 
by  trade. 

2.  Q.    Did  you  in  the  summer  of  1865,  by  direction  of  the  ordnance 
department,  carry  to  Mr.  Horatio  Ames  drawings  for  the  rilling  of  two 
guns  ? 

A.  I  went  by  the  direction  of  the  ordnance  department,  but  I  do  not 
think  I  took  the  drawings ;  I  think  Mr.  Thomas,  Mr.  Ames's  foreman, 
took  them. 

3.  Q.  Will  you  describe  the  drawings  I    How  many  different  kinds  of 
rifled  guns  were  there  ? 

A.  Two. 

4.  Q.  What  were  they  ? 

A.  One  with  the  ordinary  square  rifling  5  the  other  was  one  of  Brooks's 
rifling. 

5.  Q.  How  long  wer  you  at  Mr.  Ames's  works  ? 

A.  I  got  there  on  the  6th  of  July,  and  I  left,  I  think,  on  the  first  of 
August. 

6.  Q.  Did  you  have  opportunities  of  observing  the  manufacture  of 
guns  ? 

A.  I  did,  perfectly ;  I  took  a  great  interest  in  it,  and  saw  everything. 

7.  Q.  What  was  your  opinion  of  the  value  of  that  system,  for  making 
strong  guns? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  63 

A.  I  think  it  was  a  most  admirable  system,  the  best  I  ever  saw  ;  that 
if  iron  cannot  be  put  together  by  that  system,  there  is  none  by  which  it 
can. 

8.  Q.  The  whole  question  is  whether  welds  could  be  made  perfectly 
by  that  system.     Do  you  think  they  could  ? 

A.  Yes,  I  think  the  plan  of  presenting  the  convex  surfaces  is  the  true 
one,  and  that  thus  all  the  scoriae  is  forced  out  by  the  horizontal  hammer. 

9.  Q.  Were  you  in  the  battle  of  Fort  Fisher  ? 
A.  I  was. 

10.  Q.  Did  any  guns  burst  there  to  your  knowledge,  on  board  our  fleet  ? 
A.  Yes,  but  not  on  the  vessel  on  which  I  was,  but  on  some  in  the 

vicinity. 

11.  Q.  Did  you  understand^  that  after  guns  burst  the  charges  were 
reduced  ? 

A.  I  think  the  order  was  to  reduce  to  eight  pounds,  the  vessel  to  which 
I  was  attached  had  a  100-pouiider,  but  it  was  taken  and  laid  aside  and 
never  fired  after. 

12.  Q.  Was  it  the  opinion  that  the  excessive  charging  was  the  cause 
of  the  bursting  ? 

A.  There  were  many  opinions  expressed;  some  had  one  and  some 
another  5  I  had  my  own  opinion.  Some  thought  it  was  on  account  of 
the  construction  of  the  gun,  and  some  that  it  was  owing  to  excessive 
charging. 

13;  Q.  Was  the  efficiency  of  the  guns  reduced  by  lessening  the 
charge  ? 

A.  The  efficiency,  of  course,  depends  upon  the  power  behind  the  pro- 
ectile  j  if  you  diminish  the  power  you  diminish  the  efficiency,  of  course. 

14.  Q.  What  was  the  efficiency  of  these  guns  with  the  eight-pound 
charge  f 

A.  I  never  saw  any  experiment  with  an  eight-pound  charge ;  but  my 
own  experience  would  demonstrate  that  if  it  would  take  a  lull  charge  to 
keep  the  shot  or  shell  point  on,  and  not  have  a  rotary  motion,  by  dimin- 
ishing it,  it  would  not  go  point  on,  but  would  have  a  tendency  to  turn 
oft'. 
'  15.  Q.  Did  you  see  any  of  those  guns  after  they  were  burst? 

A.  Only  small  fragments  of  the  gun  on  board  the  Ticonderoga. 

16.  Q.  What  was  your  view  of  the  cause  of  their  bursting? 
A.  I  think  the  guns  were  improperly  made. 

17.  Q.  How? 

A.  I  do  not  think  cast  iron  is  capable  of  bearing  such  an  immense 
strain.  The  strain  being  brought  on  the  cast  iron  the  hoop  is  all  that 
holds  it. 


WASHINGTON,  D.  C.,  January^  25, 1869. 

Brevet  Brigadier  General  T.  J.  KODMAN  sworn  and  examined. 
By  the  CHAIRMAN  : 

1.  Q.  Have  you  in  any  way  the  superintendence  of  the  construction  of 
ordnance  in  the  War  Department  1 

A.  I  am  constructor  of  ordnance  of  the  ordnance  department. 

2.  Q.  Are  you  the  inventor  of  what  is  known  in  the  ordnance  depart- 
ment as  the  Rodman  system  of  fabricating  cannon  ? 

A.  Yes. 


64  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

3.  Q.  At  what  time  did  you  originate  this  system? 
A.  In  1845,  I  first  commenced  it. 

4.  Q.  When  was  it  adopted  by  the  War  Department  ? 

A.  I  think  it  can  be  said  to  have  been  first  adopted  in  1862. 

5.  Q.  When  by  the  navy  I 

A.  I  do  not  know  that  it  has  been  adopted  by  the  Navy  Department, 
except  for  12-inch  rifles,  15-inch  or  larger  smooth-bore  guns. 

6.  Q.  At  what  foundries  have  guns  been  made  upon  your  system  ? 
A.  The  first  guns  were  made  at  the  Fort  Pitt  foundry.    They  were 

then  made  at  South  Boston,  0.  Alger  &  Co. ;  at  the  Scott  foundry,  Bead- 
ing, Pa.,  Seyfort,  McManus  &  Co.;  and  at  Mr.  Parrott's,  Cold 'Spring, 
N.  Y.  There  was  one  other  that  started  to  make,  at  Providence,  R.  I., 
Builder's  iron  foundry.  No  guns  were  received  from  them  for  the  ord- 
nance department. 

7.  Q.  Who  are  or  have  been  the  proprietors  at  the  Fort  Pitt  foundry 
since  your  guns  have  been  made? 

A.  When  I  first  started  it  was  Knap  &  Totten ;  it  was  that  firm  that 
made  the  first  experiments  to  determine  the  practicability  of  casting 
guns  in  that  way.  Charles  Knap's  Nephews  was  the  style  of  the  firm 
during  the  war.  That  firm  is  now  the  Knap  Fort  Pitt  Foundry  Company. 

8.  Q.  Do  you  know  whether  any  officers  of  the  government  have  been 
interested  in  that  foundry  ? 

A.  None,  to  my  knowledge. 

9.  Q.  What  royalty,  per  cent.,  or  profit  have  you  received  on  guns 
made  according  to  your  system  ? 

A.  In  the  first  place,  I  sold  to  Mr.  Knap  my  interest  in  the  patent, 
for  which  he  was  to  pay  me  one-half  cent  per  pound  on  all  castings 
made  under  that  patent,  and  on  which  he  collected  royalty. 

10.  Q.  That  contract  still  remains  in  force  I 
A.  Yes. 

11.  Q.  Can  you  state  what  has  been  about  the  gross  amount  of  such 
profit  received  by  you  ? 

A.  I  could  not  state  it  exactly. 

12.  Q.  Can  you  tell  what  was  the  prices  -charged  the  government  at 
the  different  foundries  for  this  gun  ! 

A.  No,  I  cannot.  That  is  on  record  in  the  Ordnance  Office.  I  never 
had  anything  to  do  with  the  prices  paid  for  guns. 

13.  Q.  Will  you  now  explain  what  it  is  in  your  system  that  you  claim 
as  original,  and  for  which  you  receive  a  royalty  ? 

A.  My  recollection  is,  that  my  claim  reads  something  like  this:  "  For 
the  cooling  of  heavy  hollow  castings,  intended  to  resent  central  force,  by 
circulating  within  the  core  a  cooling  fluid  or  gas;  in  combination  with 
the  application  of  heat  on  the  exterior  to  prevent  too  rapid  cooling  from 
without." 

14.  Q.  In  what  particular  does  your  system  differ  from  the  system, 
upon  which  was  made  the  12-inch  coluinbiads  of  Colonel  Boinfordf 

A.  It  differs  in  this,  that  the  gun  cast  by  him  was  cast  solid,  and 
cooled  entirely  from  the  exterior ;  while  guns  cast  on  my  system  are 
cast  hollow,  and  cooled  in  accordance  with  my  aforesaid  claim. 

15.  Q.  Will  you  explain  the  manner  in  which  guns  are  made  upon 
Admiral  Dahlgren's  system  ? 

A.  I  do  not  know  that  Admiral  Dahlgren  has  any  system  of  casting 
guns;  he  has  a  model  and  no  other  claim  that  I  know  of;  his  guns  hav- 
ing been  cast  solid,  or  cooled  from  the  exterior,  which  is  no  novel  method 
of  cooling. 

16.  Q.  What  are  the  general  points  of  difference  of  models  between 
the  Eodman  and  the  Dahlgren  guns  ? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  65 

A.  In  theDahlgren  gun  the  reinforce  for  two  or  three  feet  between  the 
breech  and  trunnions  is  cylindrical ;  his  gun  then  tapers  rapidly  to  a 
cone,  the  chase  being  conical  j  while  in  my  model  there  is  no  straight 
line  on  the  exterior  at  all ;  his  cylinder  being  replaced  by  a  double  con- 
vex surface,  and  his  conical  chase  by  a  concave  surface ;  my  model  being 
so  constructed  that,  under  the  formula  for  the  exterior,  the  chase  may 
be  continued  to  any  extent  and  leave  a  proper  thicknesss  of  metal ; 
while  in  the  other  the  chase  being  extended  the  thickness  becomes 
nothing  a  short  distance  from  the  muzzle ;  the  taper  between  reinforce 
and  chase  being  much  less  rapid  in  my  model  than  in  his. 

17.  Q.  What  is  the  condition  of  the  metal  in  guns  cast  upon  your 
system  ? 

A.  That  depends  upon  the  rate  of  cooling  from  the  interior.  The 
intention  is,  when  the  requirements  are  carried  out,  that  the  metal  in 
the  gun  shall  be  under  a  certain  amount  of  initial  strain,  the  exterior 
being  under  a  force  of  extension  while  the  interior  is  under  one  of 
compression. 

18.  Q.  Is  this  condition  arrived  at  under  your  method  of  cooling  from 
the  interior? 

A.  Yes. 

19.  Q.  Do  you  mean  to  have  the  tension  uniform  throughout  the  wall 
of  the  gun? 

A.  No,  not  while  the  gun  is  free  from  the  strain  due  to  powder.  When 
subject  to  that  strain,  if  the  initial  strain  be  of  proper  tension,  it  would 
bring  the  whole  of  the  thickness  of  the  walls  of  the  gun  to  the  breaking 
strain  at  the  same  instant,  and  would  give  us  the  benefit  of  the  entire 
thickness  of  the  walls  of  the  gun  in  resisting  the  force  of  the  powder ; 
while  any  solid-cast  gun,  cooled  entirely  from  the  exterior,  is  under  an 
initial  strain  the  reverse  of  that  just  described,  the  exterior  being  under 
a  force  of  compression  while  the  interior  in  under  one  of  extension,  and 
the  action  of  the  powder  joins  with  the  exterior  of  the  gun  to  break  the 
interior  before  the  exterior  is  brought  into  useful  action  at  all. 

20.  Q.  Do  you  think  a  12-inch  rifle  gun  could  be  made  and  cast  of  the 
same  dimensions  and  weight  as  a  12-inch  Kodmaii  rifle,  which  could 
endure  1,000  rounds,  by  cooling  it  so  slowly  as  to  have  the  metal  in  a 
state  of  initial  rest,  or  without  strain  ? 

A.  I  should  think  it  doubtful  whether  it  would.  That  state  of  things 
would  be  better  than  that  obtained  by  casting  and  cooling  from  the  exterior. 

21.  Q.  Do  you  think  the  principle  of  initial  tension  necessary  to  be 
embodied  in  a  gun,  in  order  to  have  the  metal  perform  its  full  share  of 
work  in  restraining  the  action  of  a  force  from  within  outwards,  having 
a  tendency  to  burst  the  gun  or  injure  the  bore? 

A.  I  do  consider  it  absolutely  necessary. 

22.  Q.  Does  a  gun  which  is  cast  solid,  and  cooled  from  the  exterior, 
have  the  same  fineness  of  grain  and  texture  at  the  surface  of  the  bore 
as  a  gun  cast  hollow  ? 

A.  It  does  not. 

23.  Q.  Is  there  any  difference  in  texture  between  the  iron  in  the  cen- 
ter of  the  block  for  a  solid- cast  gun  and  the  exterior? 

A.  Yes,  very  considerable;  that  difference  increasing  with  the  size  of 
the  block. 

24.  Q.  Are  there  any  cavities  found  in  the  center  of  most  of  the  large 
size  blocks  f 

A.  Yes;  there  are  what  they  term  draws.  I  would  also  remark  that 
the  more  rapidly  the  gun  is  cooled  from  the  exterior  the  more  likely  are 
these  draws  to  appear. 

Kep.  No.  266 5 


66  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

25.  Q.  At  what  part  of  the  casting  would  they  appear,  providing  the 
gun  is  cast  to  the  shape  at  which  it  is  afterwards  to  be  finished  ? 

A.  It  would  most  likely  appear  near  the  trunnion,  just  above  where 
the  most  rapid  taper  takes  place,  the  gun  being  vertical  with  the  muzzle 
up. 

26.  Q.  Have  any  cavities  ever  been  found  in  the  hollow-cast  gun 
between  the  exterior  surface  and  the  surface  of  the  bore  T 

A.  Yes  ;  we  found  small  cavities  then.  One  of  the  guns,  cast  at  Pitts- 
burg,  was  found  to  have  small  cavities  of  that  kind. 

27.  Q.  Are  there  any  differences  of  texture  between  the  metal  nearer  the 
cooling  surface,  exteriorly  and  interiorly,  and  the  middle  metal  of  the 
wall  of  the  hollow-cast  gun  I 

A.  There  is  some  difference  which  may  be  detected  by  the  practiced 
eye ;  the  interior  is  finest-grained,  and  the  exterior  is  next — the  middle 
is  generally  the  coarsest,  though  not  always  so. 

28.  Q.  Would  such  a  cavity,  or  difference  in  texture,  indicate  that 
there  were  opposing  tensions  in  the  wall  of  the  hollow-cast  gun,  and  that 
those  tensions,  which  resulted  from  the  abstraction  of  heat  from  the 
exterior,  were  acting  to  assist  the  force  of  the  charge  to  burst  the  gun  ? 

A.  I  do  not  think  that  these  textures  would  indicate  strain  at  all  $  they 
result  from  the  difference  in  length  of  time  the  metal  has  in  cooling. 

29.  Q.  If  the  difference  in  time  of  cooling  is  not  all  that  you  depend 
upon  to  produce  the  initial  tension  which  you  desire  to  obtain,  what  is  ? 

A.  The  initial  strain  is  due  to  the  difference  in  time  of  cooling,  and 
is  produced  by  retarding  the  cooling  of  the  exterior,  so  as  to  keep  it  at 
a  higher  temperature  during  the  process  of  cooling  than  that  of  the 
interior  of  the  gun. 

30.  Q.  Is  the  point  in  the  wall  of  your  gun  which  cools  last,  the  weak- 
est ? 

A.  It  ought  to  be  the  weakest.  In  the  cooling  of  the  gun  the  heat  on  the 
exterior  is  not  sufficient  to  prevent  the  congelation  of  the  metal — it 
simply  retards  the  cooling  of  the  iron  of  the  exterior  after  the  metal  has 
solidified — and  to  retain  it  in  that  condition  while  the  interior  is  cooling, 
so  that  the  exterior,  as  it  afterward  cools,  shrinks  upon  the  interior, 
a  tire  upon  a  wheel. 

31.  Q.  Do  you  prevent  entirely  the  cooling  of  the  exterior,  or  is  that 
also  a  cooling  surface  ? 

A.  It  becomes  a  cooling  surface  toward  the  latter  part  of  the  cooling 
process.  It  is  a  cooling  surface  to  the  extent  permitted  by  the  exterior 
artificial  heat. 

32.  Q.  Then  the  portion  of  the  gun  which  cools  last  is  not  the  exte- 
rior, that  being  at  some  point  between  that  and  the  interior? 

A.  Yes  ;  that  is  the  case. 

33.  Q.  Is  it  in  that  locality  that  you  have  the  difference  of  texture  or 
the  cavities  that  you  speak  of? 

A.  Yes ;  where  they  occur.  They  are  generally  nearer  the  exterior 
than  the  interior ;  but  they  seldom  occur. 

24.  Q.  Have  you  ever  noticed  any  facts  which  showed  that  the  tension 
in  solid-cast  guns,  from  the  bore  outwards,  assisted  the  force  of  the  pow- 
der to  enlarge  the  bore  or  burst  the  gun  f 

A.  I  have  noticed  cavities  (slits  like  these  draws)  in  guns,  and  my  re- 
collection is,  that  one  gun,  having  such  cavity  or  slit,  was  fired  at  Alger's 
foundry,  about  or  previous  to  the  time  Colonel  Bornford  cast  his  12-mch 
gun  and  showed  a  very  small  endurance. 

25.  Q.  Were  such  tensions  irremedial  in  all  large  columbiads  previ- 
ous to  adopting  that  hollow  mode  of  casting  ? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  67 

A.  My  impression  is  that  they  were  to  a  greater  or  less  extent,  and 
my  system  of  cooling  was  intended  to  correct  this  defect. 

26.  Q.  We  understand,  then,  that  the  principle  object  of  the  hollow 
mode  of  casting  is  to  have  the  tension  reversed,  thereby  thus  to  assist 
the  tensile  strength  of  the  iron  to  restrain  the  force  acting  against  the 
bore  of  the  gun  to  enlarge  or  burst  it  ? 

A.  The  object  is,  as  before  stated,  to  throw  the  metal  in  a  hollow-cast 
gun  upon  an  initial  strain,  the  exterior  being  under  a  force  of  extension 
and  the  interior  Milder  'one  of  compression,  and  such,  that  under  the  law 
of  diminution  of  strain  from  the  bore  outward,  the  entire  thickness  of 
the  walls  of  the  gun  should,  under  the  action  of  the  central  force,  be 
brought  to  the  breaking  strain  at  the  same  instant. 

27.  Q.  What  is  the  effect  of  time  upon  the  tension  of  the  solid-cast 
gun,  or,  in  other  words,  would  a  solid-cast  gun  be  better  when  new  ? 

A.  I  do  not  think  that  that  point  is  known  ;  1  do  not  know. 

28.  Q.  Theoretically  what  would  be  your  opinion  ? 

A.  I  was  going  to  state  that  I  do  not  know  whether  a  piece  of  metal 
brought  under  a  given  extension  by  a  tensile  force  and  held  there  until 
it  should  accommodate  itself  to  that  extended  length,  would  be  weaker 
than  if  it  had  been  left  at  its  original  position ;  my  belief  is  that  it 
would. 

29.  Q.  Would  you  cool  a  hollow-cast  gun  at  any  different  rate,  if  it 
was  to  be  fired  to  extremity  when  new,  from  that  rate  necessary  to  its 
having  sufficient  tension  remaining  at  the  end  of  six  years  to  endure  the 
same  amount  of  firing?* 

A.  I  think  I  should  cool  a  gun  intended  to  be  used  immediately  more 
rapidly  than  I  would  one  not  to  be  used  in  eight  or  ten  years.  This  is  a 
point  in  which  experiments  are  now  in  progress.  I  have  examined  the 
tension  in  two  pieces  of  metal  taken  from  the  same  gun,  at  intervals 
varying  from  six  months  to  two  years  after  taking  it  up,  and  no  appreci- 
able difference  has  yet  been  discovered. 

30.  Q.  Do  you  think  a  hollow  cast  gun  improved  or  deteriorated  with 
age? 

A.  My  impression  is  that  a  hollow-cast  gun  must  deteriorate  after  a 
long  time ;  I  do  not  know  how  long  before  the  tension  relaxes.  I  think 
it  must  relax  until  it  reaches  the  tension  due  to  permanent  elasticity. 

31.  Q.  And  if  it  be  exactly  right  to  bring  the  whole  thickness  of  the 
gun  to  the  breaking  strain  at  the  same  time,  this  cannot  be  the  case 
after  the  initial  strain  shall  have  been  diminished  ? 

A.  No.  I  do  not  know  the  law  of  diminution  of  strain  by  time  in  cast 
iron;  but  we  do  know  that  within  and  even  considerably  above  its  limit 
of  permanent  elasticity  it  is  a  very  elastic  substance,  or  one  having  great 
longevity  of  strain. 

32.  Q.  If  a  bar  of  cast-iron  should  be  bent  nearly  to  the  breaking  point 
and  kept  there  for  any  length  of  time,  would  it  recover  its  original  form? 

A.  That  would  depend  upon  whether  it  had  been  carried  beyond  the 
limits  of  permanent  elasticity.  If  the  bar  was  strained  to  near  its  break- 
ing point  it  would  not  return. 

33.  Q.  If  a  bar  should  be  held  in  its  position  for  a  number  of  years, 
would  it  recover  as  completely  its  form  as  if  the  strain  were  immediately 
removed  ? 

A.  It  would  not. 

34.  Q.  On  page  28,  first  paragraph,  Kodman's  book,  you  say:  "These 
results  appear  to  leave  no  doubt  as  to  the  superiority  of  the  hollow  over 
the  solid-cast  guns  while  new.     What  effect  time  may  have  upon  them 
can  only  be  ascertained  by  experience ;  but  it  is  difficult  to  understand 


68  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

how  time  could  ever  so  far  change  their  relative  endurance  as  to  cause 
the  solid-cast  guns  to  surpass  those  cast  hollow  in  this  quality."  We 
understand  that  the  first  12-inch  rifle  Rodman  gun  was  made  about  six 
years  before  it  was  completely  tested  when  it  burst.  Did  you  cause  a 
solid-cast  gun  to  'be  made  at  the  same  time,  of  the  same  model,  of  the 
same  material,  and  give  it  the  same  age  for  the  relaxation  of  its  tension 
you  gave  the  Fort  Monroe  12-inch  rifle,  so  that  the  question  of  time  upon 
the  endurence  of  guns  could  be  exactly  determined"? 

A.  No;  there  was  no  cast-iron  guns  made  at  the  same  time  that  that 
one  was. 

35.  Q.  Has  the  question  of  time  upon  the  endurance  of  both  solid  and 
hollow-cast  guns  been  as  yet  satisfactorily  determined  f 

A.  It  has  not. 

36.  Q.  Do  you  know  of  any  example  of  a  smooth-bore  gun  which  has 
exhibited  a  superior  endurance,  which  endurance  was  attributed  to  the 
length  of  time  which  elapses  between  the  time  the  gun  was  cast  and  the 
date  of  its  being  proved  ? 

A.  I  do  not  think  of  any  instance  of  that  kind  now. 

37.  Q.  Did  you  ever  have  a  gun  cast  hollow,  made  of  the  same  material, 
with  the  same  tensile  strength,  density,  model,  and  calibre  as  the  gun 
cast  in  1846  and  proved  in  1852,  mentioned  on  page  217,  Wade's  book, 
and  w^hich  endured  2,552  rounds,  (while  one  made  and  proved  in  1851, 
which  was  about  one-sixth  stronger,  burst  at  72  rounds,)  for  comparison, 
by  subjecting  it  to  proof  after  the  same  time  had  elapsed,  for  the  purpose 
of  getting  absolute  knowledge  on  the  point  mentioned  in  the  sixth  para- 
graph, on  page  55,  Rodman's  book,  in  which  you  say  you  do  not  knoAv 
whether  a  gun  is  better  when  new  or  after  it  has  lain  unused  for  a  given 
length  of  time  ? 

A.  I  do  not  think  there  was.  I  have  no  recollection  of  any  experi- 
ment of  that  kind. 

38.  Q.  What  time  elapsed  between  the  casting  and  proving  of  the 
gnu  known  as  the  12-inch  Atwater  rifle  ? 

A.  I  cannot  tell  you. 

39.  Q.  Do  you  think  that  the  Atwater  system  of  rifling  had  a  tendency 
to  increase  or  diminish  the  strain  upon  the  gun  I 

A.  I  do  not  see  that  it  should  have  the  effect  to  increase  it.  My 
impression  is  that  there  were  three  12-inch  rifles  cast  at  the  Fort  Pitt 
foundry,  and  I  think  by  an  order  from  the  Navy  Department;  one  was 
to  be  rifled  on  the  Atwater  principle,  one  rifled  on  the  plan  which  the 
navy  was  to  furnish,  and  the  other  on  a  plan  furnished  by  me.  My 
recollection  also  is,  that  these  guns  were  cast  on  a  core-barrel  that  was 
too  short,  and  in  finishing  them  with  the  proper  length  of  bore  they 
bored  through  the  interior  hard  metal  around  the  core,  thus  taking  away 
the  metal  that  was  intended  to  be  hard  and  strong  to  resist  the  action  of 
the  powder  on  the  bottom  of  the  bore.  I  believe  that  all  of  these  guns 
began  to  break  at  the  bottom  of  the  bore ;  I  saw  one,  I  know,  that  was 
cracked  at  that  point. 

40.  Q.  Were  they  cooled  from  the  exterior  ! 

A.  I  do  not  know  in  what  manner  they  were  cooled ;  I  understood 
that  they  had  cooled  some  guns  by  dropping  water  into  the  bore  and 
letting  it  evaporate.  That  was  not  carrying  out  my  system.  Whether 
these  guns  were  made  in  that  way  or  not  I  do  not  know. 

41.  Q.  Do  you  thiuk  the  fault  in  casting,  to  which  you  have  referred, 
satisfactorily  accounts  for  the  difference  of  endurance  between  the 
Atwater  rifle  and  the  first  rifle  gun  of  the  same  calibre  proved  at  Fort 
Monroe. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  69 

A.  It  is  believed  that  the  casting  of  the  bore  too  short  will  partly 
account  for  it ;  the  metal  may  not  have  been  as  good,  and  I  believe  these 
guns  were  fired  with  quicker  powder  than  that  used  in  the  Fort  Monroe 
army  12-pounder  guns. 

42.  Q.  Have  no  guns  of  large  calibre,  cast  hollow  and  cooled  from  the 
interior,  burst  at  the  foundry  I 

A.  Yes ;  there  have  been  three  or  four  that  cracked  either  in  the  pit 
or  in  the  lathe. 

43.  Q.  How  do  you  account  for  that  phenomena? 

A.  On  the  principle  that  they  cooled  them  too  rapidly  from  the  interior, 
and  kept  up  the  fire  in  the  pit  too  long  and  kept  it  too  hot.  I  was  glad 
to  learn  that  guns  could  be  thus  cracked,  for  I  had  not,  till  then,  sup- 
posed it  practicable  to  cool  a  gun  so  rapidly  from  the  interior  as  to  cause 
it  to  break  from  the  exterior.  There  was  one,  I  think,  cracked  on  the 
lathe  just  as  they  commenced  to  turn  it.  These  cracked  guns  show  that 
my  system  of  cooling  covers  the  entire  field  of  initial  strain. 

44.  Q.  Have  you  noticed  any  small  ruptures  or  cracks  on  the  outside 
of  a  gun  previous  to  firing,  cast  upon  your  system  ? 

A.  I  have  noticed  such  cracks  in  one  or  two  cases  around  the  opening 
in  the  sinking  head  through  which  the  water  passes  out  after  having  cir- 
culated through  the  cavity  left  by  the  core-barrel. 

45.  Q.  Have  you  ever  noticed  any  ruptures  or  cracks  on  the  outside  of 
such  guns  less  in  extent  than  the  complete  bursting  of  the  guns,  during 
proof  or  after  firing  in  service  ? 

A.  No ;  I  never  have.  I  do  not  believe  that  we  have  received  a  gun 
that  will  begin  to  break  on  the  outside  first,  in  firing.  I  may  say  here, 
too,  that  in  the  manufacture  of  these  guns  a  ring  is  taken  off  the  sink- 
head  contiguous  to  the  muzzle,  which  ring  is  planed  through  in  a  radial 
direction  until  the  initial  strain  breaks  the  part  that  is  left  unplaned ; 
from  the  amount  that  this  ring  opens  on  the  exterior  we  deduce  the 
extension  per  inch  in  length  of  the  metal  there.  Then  knowing  the 
extension  which  the  metal  of  the  gun  will  safely  endure,  we  can  tell 
before  the  gun  is  finished  whether  or  not  it  is  over-strained,  and  no  over- 
strained gun  has  been  accepted. 

46.  Q.  Which  is  the  most  difficult  gun  to  make  to  withstand  the  pres- 
sure of  the  powder,  a  10-inch  or  a  20-inch  gun  ? 

A.  I  do  not  think  there  is  any  difference. 

47.  Q.  Do  you  think  you  could  determine  how  best  to  make  a  40-inch 
gun  upon  the  basis  of  your  experiments  with  the  20-inch  gun  ? 

A.  I  do  not  suppose  that  it  would  be  possible  to  determine  with  cer- 
tainty, from  the  fabrication  of  the  20-inch  g\m,  the  rate  of  cooling  and 
degree  of  decarbonization  of  metal  necessary  to  make  the  best  40-inch 
gun  at  the  first  trial  that  could  be  made  by  any  number  of  additional 
experiments. 

48.  Q.  Would  the  force  acting  to  rupture  a  large  gun,  with  a  proper 
charge  of  powder,  be  more  likely  to  rupture  it  than  a  small  gun  ? 

A.  The  larger  the  gun,  other  thmgs  being  equal,  the  greater  the  strain 
or  pressure  upon  the  square  inch  on  the  surface  of  the  bore.  This  results 
from  the  greater  column  of  metal  in  front  of  each  square  inch  of  surface 
pressed  by  the  gas  in  the  large  than  in  the  small  gun ;  but,  by  making 
the  powder  for  the  20-inch  gun  appropriate  to  that  gun,  it  would  have 
no  greater  maximum  pressure  on  the  bore  than  the  10-inch  with  its  appro- 
priate charge  and  powder.  I  have  no  doubt  of  being  able  to  impress 
the  same  velocity  upon  a  40-inch  shot  that  you  do  ordinarily  upon  a  10- 
inch  shot,  and  with  little,  if  any  more,  tendency  to  break  the  large  than 
the  small  guns  ? 


70  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

49.  Q.  Is  the  initial  velocity  of  the  15-inch  gun  nearly  uniform  for  like 
charges  and  elevations  ? 

A.  It  is. 

50.  Q.  And  the  same  for  other  calibres? 
A.  Yes. 

51.  Q.  Is  that  an  indication  that  the  force  of  powder  is  nearly  uni- 
form! 

A.  Yes. 

52.  Q.  Is  the  quantity  of  gas  resulting  from  the  combustion  of  a  given 
quantity,  by  bulk,  weight,  and  size  of  grain,  uniform  or  nearly  so  ? 

A.  Equal  weights  of  gunpowder,  being  equally  well  incorporated, 
ought  to  evolve  equal  volumes  of  gas,  irrespective  of  the  size  of  grain. 

53.  Q.  How  many  rifle  12  inch  guns  have  been  made  upon  your  sys- 
tem? 

A.  For  the  army  there  have  been  three  made — all  experimental. 

54.  Q.  How  many  in  the  navy? 

A.  I  think  three,  also  experimental. 

55.  Q.  Will  you  give  a  brief  history  of  the  endurance  of  these  guns  ? 
A.  The  first  12-inch  gun,  the  only  one  that  has  been  proved  to  extremity, 

has  been  fired,  I  think,  about  480  fires ;  the  records  will  show  the  exact 
number.  That  gun  burst,  as  was  supposed,  by  the  jamming  and  wedg- 
ing of  the  projectile  in  the  bore;  the  other  two  guns,  one  made  by  the 
Knap  Fort  Pitt  Foundry  Company,  and  one  at  Alger's  foundry,  have  not 
been  fired  to  exceed  four  or  five  rounds  each;  the  one  at  Fort  Delaware 
only  two  rounds  that  I  know  of.  The  gun  at  Fort  Delaware  was  made 
by  C.  Alger,  and  the  one  at  Old  Point  by  the  Knap  Fort  Pitt  Foundry 
Company. 

56.  Q.  What  is  the  present  condition  of  these  guns? 

A.  Their  present  condition  cannot  possibly  be  known  accurately;  the 
one  at  Old  Point,  from  the  breaking  of  the  projectile  in  it,  has,  I  think, 
two  lands  slightly  depressed  for  a  length  of,  say  four  inches,  at  a  dis- 
tance from  the  muzzle  of  about  four  feet.  These  guns  have  both  been 
measured  by  the  star  gauge,  and  the  enlargement  ascertained  to  be  not 
greater  than  we  have  frequently  obtained  in  the  proving  of  the  solid-cast 
smooth-bore  guns,  I  think,  from  .012  to  .017  of  an  inch.  These  guns 
have  both  been  subjected  to  extraordinary  pressures  from  the  jamming 
and  upsetting  or  breaking  of  the  projectile  inside  of  them. 

57.  Do  ordnance  officers  all  agree  that  the  breaking  or  bursting  of  the 
projectile  is  the  chief  cause  ? 

A.  No;  not  that  it  is  the  chief  cause,  for  the  reason  that  it  ought  not 
to  occur ;  but  that  it  is  a  potent  cause  when  it  does  occur,  especially 
the  upsetting  of  the  body  of  rifle  projectiles. 

58.  Q.  Can  you  give  any  account  of  the  12-inch  rifles  made  for  the 
navy? 

A.  I  cannot.    I  know  that  they  did  not  endure  satisfactorily. 

59.  Q.  Do  you  regard  either  of  the  12-inch  guns  in  the  army  as  safe  to 
be  fired  now  with  the  ordinary  charge  I 

A.  I  think  they  are  both  so. 

60.  Q.  Could  you  predict  with  any  certainty  their  endurance  ? 

A.  I  could  not;  for  the  reason  that  I  do  not  know  what  effect  may 
have  been  produced  upon  them  by  the  extraordinary  pressures  to  which 
they  have  been  subjected. 

61.  Q.  In  many  reports  of  the  bursting  of  guns  it  is  said  that  the  rup- 
ture was  supposed  to  have  occurred  from  the  breaking  or  jamming  of 
shells  in  the  bore.    Why  is  it  there  is  no  certainty  of  the  cause? 

A.  When  a  gun  bursts,  and  you  find  the  shot  fired  at  that  time  to  in- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  71 

dicate  jamming  or  wedging,  or  you  see  that  it  is  broken,  the  presumption 
is,  and  I  think  as  a  rule  a  fair  one,  that  that  was  the  cause  of  the  burst- 
ing of  the  gun  at  that  round. 


JANUARY  26, 1869. 

Brevet  Brigadier  General  T.  J.  EODMAN  recalled. 
By  the  CHAIRMAN: 

Q.  In  developing  ordnance  power  it  has  been  determined  in  your  mind 
whether  it  had  better  be  by  smooth  or  rifle  bores,  if  the  work  to  be  per- 
formed is  the  penetration  of  iron  plates'? 

A.  My  impression  is  that  you  can  penetrate  further  with  a  rifle  projec- 
tile than  with  a  smooth-bore.  But  at  moderate  distances  the  racking 
effect  upon  the  embrasure  of  a  fort  or  the  side  of  a  ship  or  turret  will  be 
greater  from  the  smooth-bore  of  the  calibres  now  known  to  be  practicable 
than  with  the  rifle.  I  would  also  add  that  the  smooth-bore  is  much  less 
liable  to  extraordinary  or  dangerous  pressures  than  the  rifle.  It  is  gen- 
erally agreed  by  ordnance  officers  of  this,  and  I  believe  other  countries, 
that  racking  is  more  destructive  of  the  plating  of  vessels  than  penetra- 
tion ;  I  understand  and  believe  it  to  be  so. 

Q.  Have  you  determined  in  your  mind  whether  it  is  better  to  load  at 
the  breech  or  at  the  muzzle  for  guns  of  large  calibre  ? 

A.  1  have  not  definitely  determined  that  question.  My  belief  is  that 
you  can  make  a  muzzle-loading  gun  stronger,  that  is,  to  resist  a  heavier 
charge,  than  a  breech-loader.  The  breech-loader  would  have  the  advan- 
tage in  embrasure,  where  it  might  close  the  port-hole  with  the  muzzle ; 
while  loading  at  the  breech  thus  prevents  the  ingress  of  small  projectiles 
during  that  time. 

Q.  Is  a  breech-loading  gun  stronger  or  weaker  than  a  muzzle-loader, 
leaving  out  of  consideration  the  strength  or  weakness  of  the  parts  which 
constitute  the  breech -loading  attachment  ? 

A.  All  the  breech-loading  guns  that  I  have  seen  are  weaker  necessarily 
than  the  muzzle-loaders,  for  the  reason  that  the  breech-loader  is  deprived 
of  a  great  part  of  the  stave  or  transverse  resistance  of  which  the  muzzle- 
loader,  has  the  benefit.  I  would  say  that  this  might  be  to  some  extent 
remedied  by  throwing  the  seat  of  the  charge  forward  in  the  gun. 

Q.  Do  you  think  that  the  central  metal  at  the  rear  of  the  bore,  reach- 
ing through  the  cascable,  adds  to  or  diminishes  the  strength  of  the  bar- 
rel of  the  gun  ? 

A.  It  adds  to  the  strength  of  the  gun. 

Q.  How  in  a  breech-loader  having  a  breech-pin  ? 

A.  It  is  not  as  strong  as  a  solid  breech. 

Q.  Have  you  ever  seen  an  example  of  a  cast-iron,  unbanded  gun,  which 
had  ruptured  longitudinally  through  the  reinforce,  in  which  the  line  of 
fracture  was  not  continued  through  the  breech  or  cascable  ? 

A.  I  have  seen  examples  where  it  was  not  continued  through  the  cas- 
cable; the  fracture  will  always  pass  through  the  breech,  more  or  less  ob- 
liquely, to  a  plane  containing  the  axis  of  the  bore.  Where  the  breech 
has  the  proper  thickness  of  metal  in  the  rear  of  the  bore  the  fracture  is 
more  likely  to  break  off  obliquely  to  the  plane  of  the  axis. 

Q.  Is  the  direction  of  fracture,  shown  in  the  various  diagrams  to  be 
found  in  the  books  usually  entitled  "Rodman's"  and  "Wade's"  books, 


72  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

the  general  direction  of  such  fractures  if  the  guns  are  made  of  cast-iron 
and  unhanded  I 

A.  They  are  for  the  model  of  the  gun  there  shown.  These  guns  dif- 
fer in  the  breech  from  my  present  model. 

Q.  Is  there  any  law  in  relation  to  the  strength  of  hollow  cylindersr 
closed  at  each  end,  subject  to  a  force  from  within,  by  which  the  differ- 
ence in  tendency  to  burst  longitudinally  or  transversely  can  be  deter- 
mined ? 

A.  I  do  not  know  that  such  a  law  has  been  determined ;  but,  practi- 
cally, that  point  can  be  determined,  and  a  result  will  be  found  in  my 
printed  report  of  experiments.  I  would  state,  too,  that  when  the  distance 
or  length  of  bore  acted  upon  by  the  internal  force  is  such  that  the  tan- 
gential expansion  of  the  metal  at  the  point  of  rupture  will  not  admit  of 
the  bending  of  the  stave  to  an  extent  required  to  rupture  it  transversely 
longitudinal,  fracture  will  take  place.  If  that  distance  be  so  short  that 
the  length  of  stave  acted  upon  will  break  transversely  before  extending 
the  metal  to  its  breaking  point  tangentially,  then  transverse  rupture  will 
first  take  place. 

Q.  Do  you  think  that  this  explanation  fully  accounts  for  the  trans- 
verse ruptures  which  have  sometimes  occurred  in  guns  of  large  calibre  I 

A.  I  do  not  know  that  it  does  fully.  We  have  transverse  ruptures  which 
occur  from  longitudinal  rupture  having  first  taken  place ;  for  instance, 
rupture  at  the  breech  may  extend  forward  until  one  piece  or  the  other 
shall  break  off  with  a  transverse  fracture  at  its  front  end. 

Q.  If  it  be  the  pressure  of  the  powder  against  the  surface  of  the  bore 
that  is  the  cause  of  the  bursting  of  guns,  how  can  you  account  for  the 
breaking  through  the  breech  to  the  rear  of  the  continuation  of  the  bore? 

A.  From  the  breech  being  too  thin,  or  from  the  metal  being  very  soft, 
thus  allowing  the  bottom  of  the  bore  to  be  pressed  back  until  interior 
annular  rupture  takes  place.  This  subject  is  illustrated  by  my  experi- 
ments on  small  cylinders  to  be  found  in  my  printed  reports,  plate  7  and 
page  153.  . 

Q.  In  treating  of  the  transverse  strain,  on  page  47  of  your  work,  have 
you  not  shown  a  form  of  fracture  which  never  occurs  to  a  gun  burst 
under  fire? 

A.  I  cannot  say  whether  I  have  or  not.  That  plate  is  intended  to  illus- 
trate the  form  of  the  fracture  that  ought  to  occur  when  transverse  frac- 
ture of  a  gun  occurs  before  longitudinal  fracture. 

Q.  Is  not  the  kind  of  fracture  you  have  shown  by  diagram  on  that 
page  the  kind  which  would  result  from  the  action  of  all  the  different 
kinds  of  strain  to  which  you  have  alluded,  viz :  "  the  tangential  strain," 
the  longitudinal  strain,  and  the  strain  of  compression  exerted  from  the 
axis  outward  I 

A.  Yes ;  when  the  surface  pressed  was  so  short  as  to  cause  transverse 
rupture  to  first  occur.  I  would  also  state  that  this  diagram  is  an  almost 
accurate  representation  of  fractures  that  occurred  in  small  cylinders, 
where  transverse  fracture  first  occurred,  as  on  plates  4  and  5  of  my 
reports. 

Q.  Yet  that  is  not  the  usual  kind  of  fracture  to  be  seen  in  guns  which 
are  burst  in  firing  I 

A.  I  do  not  know  that  I  have  ever  seen  one  of  exactly  this  form  j  for 
the  reason,  I  think,  that  the  length  of  bore  pressed  at  the  instant  when 
rupture  begins,  is  generally  greater  than  that  which  would  first  produce 
transverse  rupture. 

Q.  Then  you  think  that  the  rupture  does  not  occur  until  the  projectile 
has  made  a  start  towards  the  muzzle  ? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  73 

A.  No  •  the  projectile  will  always  have  made  some  progress  towards 
the  muzzle  before  the  breaking  strain  is  reached. 

Q.  Are  not  the  principal  pieces  forming  the  reinforce  into  which  a 
large  gun  is  usually  broken  when  it  is  burst  in  firing  most  frequently  thrown 
to  the  rear?  Would  not  that  indicate  that  the  rupture  began  forward  of 
the  trunnions  and  split  the  gun  backwards  through  the  breach  I 

A.  They  are ;  for  the  reason  that  the  gun  has  commenced  to  recoil, 
and  the  motion  of  recoil,  combined  with  their  lateral  motion,  forces  the 
pieces  obliquely  to  the  rear. 

Q.  Would  not  that  indicate  that  the  rupture  began  forward  of  the 
trunnions  to  split  the  gun  backwards  through  the  breech  ? 

A.  No. 

Q.  Is  not  the  pressure  of  the  powder  reduced  by  being  expanded  into 
the  increased  space  it  would  have  when  the  shot  had  moved  forward  in 
front  of  the  trunnions ;  can  there  be  force  enough  left  to  start  the  rup- 
ture at  that  point  first,  when  it  is  remembered  that  the  time  of  the  action 
of  the  force  against  that  part  of  the  bore  is  so  much  less  than  the  time 
of  action  in  the  chamber  ? 

A.  The  pressure  of  the  gas,  after  it  has  attained  its  maximum  pressure, 
diminishes  as  the  shot  moves  forward,  and  rupture  ought  not  to  take 
place  forward  of  the  trunnions  in  a  properly  modelled  gun. 

Q.  Does  it  take  place  in  a  model  of  your  own  u? 

A.  I  do  not  think  it  does,  unless  from  the  breaking  or  jamming  of  a 
shot  or  shell  in  the  chase  of  the  gun.  I  have  not  seen  one  broken  that 
indicated  that  it  had,  without  this  cause. 

Q.  Can  you  tell  at  what  point  the  gun  would  commence  to  rupture,  if 
you  knew  at  what  point  in  the  bore  the  projectile  jammed'? 

A.  It  ought  to  commence  at  the  thinnest  part  of  the  gun,  behind  the 
projectile,  or  at  its  then  position. 

Q.  Are  not  the  fractures  of  the  hollow  cylinders,  shown  by  shaded 
drawings  following  page  144  of  your  book,  principally  like  the  theo- 
retical fracture  shown  on  page  47  ? 

A.  Some  of  them  are  and  some  are  not. 

Q.  Is  it  not  noticeable  that  but  few  of  the  fractures  of  these  cylinders 
are  through  the  breech  part,  as  we  see  them  in  most  the  large  guns 
which  have  burst  in  firing  ? 

A.  Yes ;  and  for  the  reason  that  the  thickness  of  metal  in  the  breech 
of  the  cylinder  was  proportionally  greater  than  that  in  the  gun. 

Q.  Do  you  think  a  10-inch  gun-block,  cast  solid  and  bored,  as  if  for  a 
gun,  and  before  it  was  turned  on  the  outside,  subjected  to  water  pres- 
sure, could  be  burst  in>  such  a  manner  as  to  have  the  fracture  through 
the  breech  the  same  as  the  fracture  usual  in  the  gun  burst  by  firing  ? 

A.  I  think  it  might. 

Q.  Would  the  longitudinal  tension  in  a  similar  block,  cast  hollow, 
have  the  tendency  to  direct  the  fracture  through  the  breech,  or  other- 
wise? 

A.  I  think  it  would  have  a  tendency  to  extend  the  fracture  through 
the  breech,  which  would  increase  the  strength  of  the  gun. 

Q.  Opposite  page  13  of  your  work  there  is  a  diagram  of  a  10-inch  col- 
umbiad,  number  332,  cast  solid,*  looking  at  the  diagram,  would  you 
think  the  fracture  began  forward  of  the  trunnions  or  at  the  breech  end  ? 

A.  At  the  breech,  unquestionably. 

Q.  On  page  14  you  say  (referring  to  the  gun  last  mentioned,  and  to 
the  hollow  cast  10-inch  gun,  No.  331,  which  burst  also)  that  it  is  quite  evi- 
dent that  the  fracture  began  at  the  breech  in  both  cases  ;  yet  the  large 
piece  of  the  reinforce  from  the  hollow-cast  gun  was  thrown  to  a  great 


74  EXPEEIMENTS  ON  HEAVY  ORDNANCE. 

height,  and  to  the  rear.  Would  not  that  indicate  that  the  rupture 
began  first  at  the  front  ? 

A.  No  $  for  the  reason,  as  I  said  before,  this  rear  motion  conies  from 
recoil. 

Q.  Is  that  sufficient  to  project  the  exploded  part  to  the  rear  in  the 
manner  described  ? 

A.  Yes ;  I  think  so. 

Q.  On  page  14  you  say  (referring  to  the  splitting  of  guns  through  the 
breech)  this  has  been  the  case  with  every  columbiad  you  have  ever  seen 
broken  and  indicates  the  breech  as  the  weak  point.  Has  any  greater 
strength  been  added  to  guns  which  have  been  made  since  5  and  if  so,  has 
the  fracture  been  different  in  such  guns  I 

A.  A  greater  strength  has  been  added  to  the  breech  in  my  model  of 
gun.  I  cannot  say  whether  the  nature  of  the  fracture  has  been  changed 
or  not. 

Q.  If  you  should  find  the  character  of  the  fracture  to  be  the  same,  do 
you  think  you  could  remedy  it  by  adding  still  greater  strength  to  the 
breech  ? 

A.  I  have  no  doubt  of  it. 

Q.  Are  you  aware  that  the  first  15-inch  hollow-cast  guns  made  for 
the  navy  were  about  three  feet  shorter  than  the  army  15-inch  gun  to 
accommodate  them  to  the  diameter  of  the  turrets  ? 

A.  I  know  that  they  were  considerably  shorter ;  but  exactly  how  much 
I  do  not  know.  They  were  also  thinner  at  the  muzzle.  The  wall  or 
metal  was  about  three  inches  thick  at  the  muzzle,  while  in  my  model  a 
15-inch  gun  which  is  longer  is  five  inches  thick  at  the  muzzle.  I  do  not 
know  what  the  model  of  the  navy  gun  was  as  cast. 

Q.  What  is  the  thickness  of  wall  at  the  muzzle  in  the  army  15-inch 
gun? 

A.  The  thickness  of  the  finished  gun  is  as  before  stated  five  inches, 
the  diameter  of  the  cast  gun  at  the  muzzle  is,  I  think,  38  inches. 

Q.  Have  you  been  informed  that  three  of  the  15-inch  guns  of  the  eight 
used  against  Fort  Fisher  burst  at  the  muzzle  ? 

A.  I  have  understood  that  some  15-inch  guns  did  ;  I  do  not  know  what 
number. 

Q.  Would  those  guns  be  stronger  if  made  still  thicker  than  seven 
inches  ! 

A.  Yes ;  they  undoubtedly  would  be  if  under  proper  initial  strain ;  those 
that  burst  were  not  seven  inches  thick,  nor  anything  like  it,  being  as 
before  stated  only  about  three  inches  thick  at  the  muzzle. 

Q.  Are  you  aware  that  the  navy  reduced  the  thickness  of  the  muzzle 
afterward  to  about  three  inches,  and  reported  that  the  gun  was  not  weak- 
ened thereby  ? 

A.  I  do  not  remember  that  they  reduced  their  guns  after  the  burst- 
ing of  those  at  Fort  Fisher ;  I  am  aware  that  they  did  reduce  them  below 
the  thickness  of  the  army  gun  in  order  to  get  them  through  their  small 
port-holes. 

Q.  What,  in  your  opinion,  has  caused  the  bursting  of  navy  15-inch 
guns,  and  some  of  the  larger  Parrott  s,  at  the  muzzle  ? 

A.  The  bursting  of  the  navy  15-inch  gun  I  have  no  doubt  was  due, 
either  to  the  want  of  metal  about  the  muzzle,  or  to  the  bursting  of  shells 
within  the  gun.  In  the  Parrott  gun  the  bursting  may  have  been  due  to 
the  bursting  of  the  projectile  in  them ;  but  I  think  the  most  potent  cause 
was  the  too  rapidly  increased  twist  in  the  chase  of  the  Parrott  gun.  I 
have  examined  the  fracture  in  some,  and  found  it  to  be  very  nearly  of 
the  same  character  as  fractures  produced  in  hollow  cylinders  by  torsional 
strain. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  .         75 

Q.  If  it  should  be  demonstrated  that  guns  with  three-inch  thickness 
of  wall  at  the  muzzle  had  more  endurance  than  those  with  seven-inch 
thickness  of  wall,  how  would  you  account  for  it? 

A.  I  should  account  for  it  on  the  supposition  that  there  was  an  adverse 
initial  strain  on  the  metal  in  the  thicker  gun,  independently  of  any 
action  of  the  powder. 

Q.  Is  not  the  strength  of  the  wall  of  the  muzzle  to  resist  a  rupturing 
force  from  within  improved  by  turning  off  the  outside  metal  which  exerts 
an  opposing  tension,  as  referred  to  in  one  of  the  previous  questions? 

A.  Not  in  the  hollow-cast  gun,  nor  in  any  gun  under  a  proper  initial 
strain. 

Q.  Would  a  shell  exploding  prematurely  in  the  muzzle  of  a  gun  cause 
a  deep  indentation,  which  would  remain  as  evidence  of  the  force  if  it 
should  burst  the  gun? 

A.  The  chances  are  that  it  would. 

Q.  Have  you  ever  noticed  any  such  indentation  in  the  surface  of  the 
bore  at  the  place  of  rupture,  which  would  enable  you  to  determine  that 
such  a  force  had  acted  to  burst  the  gun  ? 

A.  I  have  not  examined  any  of  the  15-inch  guns  broken  at  Fort  Fisher. 

Q.  If  the.  projectile  did  not  make  any  indentation,  crack,  or  enlarge- 
ment, which  could  be  seen  after  a  premature  explosion,  could  the  gun  be 
injured  to  an  extent  which  would  cause  it  to  give  way  afterwards  with  a 
shell  which  did  not  burst,  and  have  the  subsequent  rupture  reasonably 
attributed  to  the  previous  premature  explosion? 

A.  That  might  or  might  not  be  with  a  rifle  projectile.  I  can  under- 
stand that  it  might  wedge  so  tight  as  to  produce  a  strain;  such  as  to  so- 
far  weaken  the  gun  that  it  might  break  at  a  subsequent  fire  and  not 
visibly  mark  the  bore.  It  is  a  matter  of  record  that  in  proving  solid- 
cast  guns  they  have  stood  the  proof  of  double  charges  and  double  shot, 
and  burst  at  the  first  service  charge  after. 

Q.  Have  there  been  any  experiments  that  have  ascertained  positively 
whether  the  premature  explosion  of  shells  in  the  bore  of  a  gun  will 
rupture  it? 

A.  1  do  not  know  of  any. 

Q.  What  is  your  opinion  ? 

A.  My  opinion  is  that  the  explosion  of  the  shell  in  the  bore  of  a  gun 
subjects  the  gun  to  an  undue  strain,  which  may  or  may  not  be  sufficient 
to  burst  it. 

Q.  What  is  the  meaning  the  term  work,  referred  to  in  modern  essays 
on  artillery,  in  relation  to  projectiles,  and  what  is  the  footpound  or  foot 
ton  referred  to  in  that  connection  ? 

A.  The  foot  pound  is  one  pound  avoirdupois,  raised  one  foot  vertical 
lift. 

Q.  Is  there  not  an  equivalent  of  heat  for  foot  pounds  or  tons,  and  a 
mechanical  equivalent  of  foot  pounds  for  a  unit  of  heat,  called  Joule's 
equivalent? 

A.  Undoubtedly  so.  The  present  theory  is  that  heat  and  work,  or 
living  force,  are  convertible  one  into  the  other,  or  that  heat  is  due  to 
molecular  motion. 

Q.  What  is  the  mechanical  equivalent  for  a  unit  of  heat? 

A.  I  do  not,  with  certainty,  remember  that  now.  I  believe  it  is  stated 
to  be  that  amount  of  heat  or  fire  effort  necessary  to  raise  one  pound  of 
water  one  degree  in  temperature,  and  that  its  equivalent  in  work  is  equal 
to  raising  774  pounds  one  foot  high;  I  am  not  positive  as  to  the  figures. 

Q.  Would  it  not  be  possible  to  determine  the  amount  of  tension  in  a 
hollow-cast  15-inch  gun,  upon  the  basis  of  the  units  of  heat,  proportioned 


76          -  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

to  the  whole  number  in  the  melted  iron,  communicated  to  the  water 
flowing  through  it,  and  upon  the  equivalent  in  foot  pounds  for  that 
heat? 

A.  I  do  not  now  see  how  you  could  do  it.  If  you  knew  just  how  much 
of  that  heat  was  taken  off  from  the  surface  of  the  bore,  and  how  much 
from  the  exterior,  and  the  times  at  which  they  were  taken  off,  I  suppose 
an  approximation  to  the  strain  or  tension  upon  the  metal  could  be  made ; 
but  I  should  greatly  prefer  to  rely  upon  the  results  obtained  from  the 
ring  taken  from  the  muzzle  of  the  gun  to  a  calculation  made  on  this 
basis. 

Q.  If  a  sufficient  number  of  shots  were  fired  from  the  15-inch  gun 
with  a  sufficient  rapidity,  and  each  of  them  upset  or  fitted  so  tightly  in 
the  bore  as  by  friction  of  rubbing  against  its  surface  to  retard  its  motion 
to  the  extent  which  would  just  permit  each  shot  to  move  .to  the  muzzle 
and  stop,  having  expended  all  the  force  of  the  powder,  sufficient  heat 
would  result  to  melt  the  gun  to  the  same  state  of  fluidity  from  which  it 
was  cooled  when  cast,  would  it  not? 

A.  Undoubtedly  sufficient  heat  would  result  from  a  sufficient  number 
of  shots  fired  with  a  sufficient  rapidity;  but  I  know  of  no  means  of  accom- 
plishing that  feat  at  this  time. 

Q.  Might  not  the  tensions  in  a  hollow-cast  gun  be  so  increased  by 
friction,  resolved  into  heat  in  this  manner,  as  to  burst  it  ? 

A.  Not  with  our  present  means  of  rapidity  of  firing,  and  a  gun  having 
a  proper  initial  strain. 

Q.  Is  it  not  more  probable  that  the  friction  which  results  in  heat, 
communicated  so  suddenly  to  the  surface  of  the  bore  near  the  muzzle, 
is  the  cause  of  the  rupture  of  guns  at  that  part,  than  that  the  bursting 
of  shells  in  the  muzzle  is  the  cause  of  the  bursting  of  the  gun  f 

A.  I  do  not  think  so. 

Q.  Which  would  create  the  most  friction  against  the  surface  of  the 
bore,  a  rifle  projectile  or  a  spherical  projectile  f 

A.  A  rifle  projectile. 

Q.  Do  you  think  that  the  additional  heat  communicated  by  the  fric- 
tion of  the  projectile  upon  the  bore  of  rifle  guns  acts  to  any  great  extent 
as  an  additional  force  to  aid  the  powder  in  rupturing  the  gun? 

A.  I  do  not.  In  a  gun  free  from  strain  when  fired,  additional  heat 
communicated  to  the  interior  of  the  metal  beyond  that  of  the  exterior 
will  increase  its  resistance ;  for,  generally,  in  guns  where  the  initial  strain 
is  too  small,  additional  heat  at  the  interior  will  increase  its  resistance ; 
while  in  those  where  the  initial  strain  is  too  great,  excess  of  heat  of  the 
interior  over  the  exterior  acts  to  diminish  their  resistance. 

Q.  Have  you  ever  made  any  estimate  of  the  number  of  degrees  the 
surface  of  the  bore  would  require  to  be  raised  suddenly  in  temperature 
in  order  to  burst  the  hollow-cast  gun  I 

A.  No,  I  have  not.  I  know  this,  though,  that  the  expansibility,  per 
inch  in  length,  of  good  gun  metal  (cast-iron)  is  about  .003"  of  an  inch, 
while  the  expansion  of  cast-iron  from  32°  to  212°  is  put  down  in  the 
books  at  a  little  over  .001"  of  an  inch  per  inch  in  length.  It  would, 
therefore,  require  a  gun  to  have  an  initial  strain  which  would  produce 
at  least  .002"  of  an  inch  extension  per  inch  in  length,  on»the  exterior 
of  the  gun,  in  order  that  a  difference  of  temperature  between  the 
interior  and  exterior  of  180°  should  at  all  endanger  its  safety. 

Q.  In  speaking  of  the  tensions  which  result  from  cooling  a  gun  from 
the  interior,  in  answer  to  a  previous  question,  you  only  referred  to  the 
tangential  strain.  Would  there  -not  also  be  a  longitudinal  contraction 
of  the  outsifte  after  the  freezing  of  the  interior  I 

A.  Certainly  there  would. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  77 

Q.  What  would  be  the  effect  of  inserting  heated  shot  in  the  bore  of  a 
gun  so  strained  tangentially  and  longitudinally? 

A.  The  tendency  would  be  to  unduly  increase  the  initial  strain  of  a 
gun  that  was  already  under  a  proper  initial  strain  before  its  insertion. 

Q.  Would  the  effect  of  this  force  generated  by  the  heat  be  to  enlarge 
the  bore  of  the  gun  ? 

A.  It  would  have  the  effect  to  enlarge  the  bore  of  the  gun,  and  to 
increase  the  initial  strain  if  a  proper  one,  and  to  diminish  it  if  an 
improper  one,  before  its  application. 

Q.  Whatever  force  tends  to  enlarge  the  bore  of  a  gun  is  a  force 
having  a  tendency  to  rupture  the  gun,  is  it  not  ? 

A.  That  depends  entirely  upon  the  condition  of  the  gun  as  to  initial 
strain  before  the  application  of  such  force,  and  upon  the  nature  of  the 
force.  If  the.  force  result  from  excess  of  heat  on  the  interior  of  the  gun, 
it  would  be  beneficial  where  the  initial  strain  is  much  too  small,  and 
hurtful  where  it  is  too  great.  If  the  force  be  purely  a  mechanical  one, 
its  tendency  will  be  in  all  cases  to  burst  the  gun. 

Q.  On  page  47  of  your  book  a  diagram  is  shown  dividing  a  cross- 
section  of  a  gun  into  voissoirs  or  staves,  and  you  speak  of  the  effect  of 
pressure  as  having  a  tendency  to  bend  these  staves  outward  in  the  mid- 
dle of  their  length,  as  shown  by  the  first  diagram  on  the  page.  The 
effect  of  cooling  from  the  interior  edge  of  the  stave  is  to  reverse  that 
curve  and  give  each  imaginary  stave  the  strong  tendency  to  burst  the 
other  way,  is  it  not  ? 

A.  It  would.  The  effect,  however,  is  beneficial  in  a  gun  having  a  proper 
or  too  small  an  initial  strain,  as  it  increases  the  length  of  the  bore,  along 
which  the  transverse  resistance  acts  beneficially. 

Q.  Then,  if  any  heat  should  be  added  to  the  inner  edge  of  the  stave 
afterwards,  when  the  gun  is  in  use,  the  tendency  to  still  further  bend  it 
would  result,  would  it  not? 

A.  It  would.  And  to  still  further  increase  the  length  of  bore  that 
would  offer  transverse  resistance,  unless  the  initial  strain  were  already 
too  great. 

Q.  Will  not  this  tendency  to  bending  outward  of  the  staves  from  after 
heating  the  gun  cast  hollow,  from  the  direct  communication  of  the  heat 
of  the  powder,  gas  in  motion,  or  the  indirect  heat  which  may  result  from 
the  friction  of  the  shot,  account  for  the  breaking  of  the  gun  through  the 
breach  ? 

A.  No;  not  unless  the  gun  be  previously  under  an  unduly  great  initial 
•  strain. 

Q.  Is  there,  ordinarily,  much  heat  communicated  to  the  surface  of  the 
bore  by  contact  with  the  hot  gas  of  the  powder? 

A.  There  is  considerable  heat  communicated;  but  the  conducting 
powers  of  the  metal  are  such  as  to  disseminate  the  heat  communicated 
to  the  bore  through  the  mass  of  the  metal,  so  as  to  render  the  difference 
in  temperature  between  the  inner  and  outer  surface  of  the  bore  so  small 
as  not  to  be  injurious  with  our  present  most  rapid  rate  of  firing  upon  a 
gun,  either  free  from  strain  or  having  a  proper  initial  strain. 

Q.  Is  the  fact  that  there  is  not  more  heat  communicated  partly  because 
gasses  are  non-conductors  of  heat,  and  after  the  gas,  which  is  in  actual 
contact,  has  given  off  its  increment  of  heat,  it  becomes  comparatively 
cold  and  is  then  interposed  as  a  non-conductor  between  the  hotter  gas 
and  the  surface? 

A.  I  think  that  may  be  so. 

Q.  Where  a  current  of  hot  gas  is  passing  rapidly  over  the  surface,  is 
the  condition  changed  to  any  degree! 


78  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  The  condition  would  undoubtedly  be  changed,  and  more  heat  would 
be  communicated  in  a  given  time. 

Q.  Would  net  the  surface  of  the  vent  receive  more  heat  on  this  account 
than  any  other  equal  surface  in  the  bore  of  the  gun? 
A.  Undoubtc  dly  it  would. 

Q.  Do  you  tLink  the  heat  which  is  communicated  to  the  metal  which 
surrounds  the  vent  has,  by  causing  a  cylinder  of  metal  which  has  the 
vent  for  its  axis  to  expand  unduly,  any  tendency  to  cause  the  line  of 
fracture  when  a  gun  bursts  to  intersect  the  vent  ? 

A.  I  have  no  doubt  that  it  has  a  tendency  that  way,  but  it  is  not  so 
great  as  invariably  to  cause  the  fracture  to  pass  through  the  vent. 

Q.  Do  you  not  think  that  the  increased  amount  of  heat,  which  will  be 
communicated  from  the  rapid  passage  of  the  hot  gas  past  the  windage, 
over  the  top  of  the  shot,  has  the  tendency,  by  heating  the  top  of  the  bore 
over  the  shot  more  than  any  other  part,  a  tendency  to  cause  the  plane  of 
fracture  to  take  the  direction  usually  observed  to  be  perpendicular? 

A.  I  don't  know  that  it  would. 

Q.  Within  certain  limits,  and  in  a  gun  not  having  tension  enough  to 
resist  the  pressure  of  the  powder  in  the  best  manner,  might  it  not  have 
increased  strength  to  resist  the  pressure  if  it  were  heated  from  within 
to  the  extent,  for  instance,  that  would  just  create  the  best  degree  of 
tension  ? 

A.  Yes ;  a  gun  not  having  sufficient  initial  strain  might  be  brought 
to  it  by  heating  the  interior. 

Q.  Do  you  think  that  guns  cast  solid  would  be  stronger  after  having 
become  heated  by  successive  fires  to  a  certain  extent  ? 

A.  I  do.  My  experience  is,  that  in  firing  solid-cast  guns  to  extremity 
they  are  more  likely  to  burst  at  the  first  fire  in  the  morning  than  at  any 
other  time  ;  and  that  they  would  have  stood  a  greater  number  of  rounds 
if  the  firing  had  been  continued  while  the  gun  was  warm,  I  doubt  not. 

Q.  Then  it  is  not  true  that  the  gun  that  is  so  constructed  as  to  embody 
the  degree  of  initial  strain  necessary  to  its  restraining  the  elastic  pres- 
sure which  the  powder  exerts  in  the  most  effective  manner  is  put  in  the 
worst  state  of  tension  as  regards  its  ability  to  resist  the  force  with  which 
its  interior  would  enlarge  as  it  is  heated  by  the  gas  or  the  friction  of  the 
powder  or  projectile  upon  its  interior  surface  ? 

A.  If  no  margin  had  been  allowed  for  the  effects  of  the  heat,  on  the 
interior,  in  fixing  the  initial  strain,  the  interior  heat  would  act  injuri- 
ously. 

Q.  Then  you  think  if  the  gun  had  too  much  or  too  little  tension  it 
would  be  in  a  bad  condition  to  resist  the  expansive  forces  of  heat  ? 

A.  If  the  gun  had  a  too  great  initial  strain,  interior  heat  would  act 
injuriously ;  if  it  had  too  little  initial  strain,  it  would  act  beneficially. 

Q.  How  if  it  had  no  initial  strain  at  all  ? 

A.  It  would  act  beneficially  ;  if  the  initial  strain  had  been  adverse  it 
would  also  be  beneficial,  and  in  a  still  higher  degree. 

Q.  Was  the  firm-name  or  style  Knapp  &  Wade  at  any  time  during 
your  experience  with  the  Fort  Pitt  foundry  ? 

A.  Either  Knapp  &  Wade,  or  Knapp,  Wade  &  Co.,  I  am  not  positive 
which,  was  the  style  of  the  foundry  at  one  time. 

Q.  Do  you  know  whether  Major  Wade  was  at  any  time  a  partner  in 
the  Fort  Pitt  foundry  while  he  was  in  service  as  an  officer  of  the  army 
or  a  clerk  in  the  Ordnance  Office  ? 

A.  I  have  no  positive  knowledge  on  the  subject ;  but  my  firm  belief  is 
that  he  was  never  connected  with  the  foundry  as  partner  while  in  the 
employ  of  the  government  in  any  capacity. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  79 

Q.  What  was  the  date  of  the  last  patent  issued  to  you  or  to  Mr.  Knapp 
for  the  hollow  mode  of  casting  guns  ? 

A.  I  only  had  one  patent.  My  recollection  is  that  that  was  issued  in 
August,  1847,  and  renewed  in  August,  1861,  for  seven  more  years,  and 
that  it  expired  in  August  last. 

Q.  Has  any  patent  for  the  same  thing,  or  for  a  similar  invention,  been 
given  to  Mr.  Knapp  or  any  other  parties  ? 

A.  No,  not  to  my  knowledge. 

Q.  Have  you  applied  for  still  further  extension  ? 

A.  No,  I  have  not. 


JANUARY  27, 1869. 
Brevet  Brigadier  General  T.  J.  EODMAN  recalled. 

By  the  CHAIRMAN  : 

Question.  You  informed  us  yesterday  that  work  and  heat  are  con- 
vertible. Are  we  to  understand  you,  from  that  statement,  that  as  one  is 
expended  the  other  is  evolved,  and  vice  versa  ? 

Answer.  Yes ;  or,  in  other  words,  the  living  force  of  work  stored  up 
in  a  shot  in  motion,  for  example,  will,  on  arresting  or  reducing  the  veloc- 
ity of  the  shot,  be  converted  into  heat  or  molecular  motion.  The  quan- 
tity of  heat  developed  and  the  work  remaining  in  the  shot  at  any  instant 
of  time  being  together  exactly  equal  to  the  quantity  of  work  originally 
in  the  shot. 

Q.  Will  you  state  the  average  rate  of  extension,  per  inch,  within  rup- 
turing, for  gun  iron  ? 

A.  It  will  run  from  .0025"  to  about  .0035"  of  an  inch  per  inch  in 
length ;  the  best  ought  to  extend  (.0035")  3£  thousandths  of  an  inch  per 
inch  in  length,  before  breaking. 

Q.  Also  the  average  rate  of  extension  per  inch  within  permanent  elas- 
ticity for  gun  iron '? 

A.  Good  gun  iron  will  run  from  8  to  12  thousand  pounds  per  square 
inch,  while  its  permanent  elasticity  will  not  be  sensibly  or  very  injuriously 
impaired  inside  of  15,000  pounds.  I  find  in  this  sample,  tested  here, 
(referring  to  the  book,)  the  absolute  limit  of  permanent  elasticity  is 
9,000  pounds  per  square  inch;  the  specimen  extended  (.00043")  Toinroo^ 
of  an  inch,  having  a  permanent  set  of  (.00001")  1 0  ^  0  0  of  an  inch ;  and 
at  15,000  pounds  the  same  specimen  extended  (.00080")  TQ^O¥  °f  ari 
inch,  and  had  a  permanent  set  of  (.00007")  jo-oWo  °f  an  inch- 

Q.  What  is  the  additional  temperature,  in  degrees,  which  gives  expan- 
sion per  inch  equal  to  the  extension  to  the  limit  of  permanent  elasticity  ? 

A.  That  would  require  some  calculation. 

Q.  Could  you  approximate  it  ? 

A.  It  would  take  about  80°  to  expand  the  metal  to  an  extent  equal  to 
the  extension  for  good  cast-iron  at  the  limit  of  elasticity. 

Q.  What  increase  of  temperature,  in  degrees,  will  give  expansion  per 
inch  equal  to  the  average  extension  to  the  breaking  point? 

A.  It  would  take  about  600°,  supposing  the  expansion  of  the  metal  to 
be  uniform  between  the  limits  of  32°  and  that  point. 

Q.  What  was  the  difference  of  the  rate  of  cooling  employed  when  a 
15-inch  gun  was  cast  which  ruptured  longitudinally  in  the  pit,  and  the 
one  to  which  you  have  alluded,  as  showing  that  your  mode  of  cooling- 
did  give  the  required  initial  strain — i.  e.,  what  was  the  difference  of 
temperature  between  the  exterior  and  the  interior  at  the  instant  each 
froze? 


80  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A.  I  do  not  know  what  the  exact  condition  of  the  temperature  was. 
My  impression  is  that  the  metal  was  at  the  same  temperature  inside  as 
p.ut  when  it  congealed;  but  I  have  no  doubt  that  it  congealed^rstf  on  the 
inside. 

Q.  You  have  stated  that  you  accelerate  the  time  of  cooling  a  hollow 
gun  to  about  half  the  time  required  to  cool  it  entirely  from  the  exterior. 
What  is  the  time  usually  required  to  cool  a  hollow  cast  15-inch  gun,  and 
is  the  time  nearly  uniform  for  that  size  of  gun  ? 

A.  It  is  almost  uniform ;  it  is  intended  to  be  uniform,  and  generally 
occupies  about  six  days. 

Q.  What  difference  of  temperature  between  the  interior  and  the 
exterior,  while  cooling,  have  you  noticed  as  giving  the  best  state  of 
strain  in  a  gun  cast  hollow  ! 

A.  We  have  not  been  able  to  determine  the  temperature  of  the  gun 
itself  upon  the  exterior ;  we  have  only  ascertained  the  temperature  of 
the  pit  in  which  the  gun-flasks  were,  and  the  change  in  temperature  of 
the  ingoing  and  outcoming  water.  My  recollection  is  that  the  tempera- 
ture of  the  water  is  about  156°  as  it  comes  out  just  after  casting ;  it 
would  come  up  to  that  as  the  highest  point  while  the  water  circulated 
through  the  core-barrel.  After  the  core-barrel  is  removed  the  water 
circulates  through  the  cavity  left,  by  which  the  water  is  raised  to  a 
temperature  something  less  than  212°,  so  that  it  does  not  make  steam ; 
this  temperature  gradually  recedes.  As  the  gun  cools,  the  temperature 
of  the  pit  is  generally  from  500°  to  600°  during  the  first  two  days ;  then 
the  pit  gradually  cools  as  the  gun  cools,  the  water  circulating  all  the 
while. 

Q.  Heretofore,  in  speaking  of  cast-iron,  you  have  called  it  a  good  con- 
ductor, saying  that  heat  was  quickly  dispersed  throughout  the  mass. 
Is  it  a  worse  conductor  while  it  is  being  cooled  in  the  foundry  pit ;  if 
not,  how  can  there  be  so  great  a  difference  between  the  interior  and 
exterior  while  a  gun  is  being  cooled  ? 

A.  In  cooling  a  gun  from  the  casting  temperature  we  start  with  a 
very  high  temperature,  so  that  the  difference  in  temperature  between 
the  interior  and  exterior  cooling  surfaces  is  very  great,  that  of  the 
interior  being  not  above  200°,  while  the  exterior  is  at  a  red  or  even  a 
white  heat ;  and  wTe  know  that  the  greater  the  difference  in  temperature 
of  the  heat-receiving  surfaces,  the  greater  will  be  the  difference  in  tem- 
perature of  the  heat-imparting  surfaces;  or  the  more  rapidly  a  body 
receives  or  parts  with  heat  the  greater  will  be  the  difference  in  tein- 
derature  at  the  surface,  and  at  a  given  distance,  within  the  body,  from 
its  surface.  In  practice,  in  firing  heavy  artillery,  the  heat  is  so  slowly 
applied  that  the  difference  in  temperature  of  the  exterior  and  interior 
surfaces  of  the  gun  isnever  great. 

Q.  General,  here  is  a  target  record  of  the  firing  of  the  12-inch  Rod- 
man rifle  gun,  which  burst  at  Fort  Monroe  at  the  472d  round.  Will  you 
please  examine  it  and  inform  us  if  the  record  shows  the  cause  of  the 
bursting  of  the  gun  I 

A.  The  only  thing  that  would  indicate  the  cause  of  the  bursting  at 
that  round  is  the  indication  of  the  shot  having  jammed  in  the  bore  of 
the  gun,  as  shown  by  the  impression  of  the  lands  of  the  gun  upon  the 
surface  of  the  shot. 

Q.  What  is  the  character  of  fracture  ! 

A.  The  fracture  is  longitudinal,  and  deviated  when  it  reached  within 
about  four  feet  of  the  muzzle — a  little  shorter  on  one  side  than  the  other. 

Q.  Would  this  fracture  indicate  that  the  breech  was  not  thick  enough  ? 

A.  Yes ;  that  would  indicate  that  the  gun  would  be  strengthened  if 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  81 

the  thickness  of  the  breech  was  increased;  however,  though  the  line  of 
fracture  should  run  through  the  middle  of  the  gun,  leaving  the  two  sides 
almost  equal,  it  would  not  necessarily  indicate  that  the  breech  was  too 
weak. 

Q.  In  what  part  of  this  gun  do  you  think  the  rupture  began? 
A.  My  impression  is  that  it  began  at  the  rear  part  of  the  gun ;  it  is 
possible  that  it  may  have  commenced  at  the  fore  part  of  it,  though  the 
manner  in  which  it  broke  indicated  that  the  crack  was  running  forward 
at  the  point  where  transverse  rupture  first  occurred. 
Q.  Was  the  distance  any  of  the  parts  were  thrown  great  ? 
A.  About  21  yards  seems,  from  the  report,  to  be  the  greatest  distance 
to  which  any  of  the  pieces  were  thrown. 
Q.  What  was  the  direction  in  which  the  parts  were  thrown  ? 
A.  About  10°  to  the  rear,  I  believe.    I  understand  that  two  fell  on  the 
right,  about  10°  to  the  rear,  from  a  perpendicular  line  to  the  right,  across 
the  line  of  fire. 

Q.  Is  it  probable  that  any  of  the  parts  were  thrown  upward  to  a  great 
height  ? 

A.  I  think  not,  from  this  fracture,  (referring  to  a  drawing  shown.) 
Q.  Were  there  any  cracks  or  flaws  shown  on  the  surface  of  the  bore 
previous  to  the  rupture  ? 

A.  It  is  said  here,  referring  to  report,  that  none  were  discovered.  I 
examined  one-half  of  the  gun  myself  after  it  was  broken,  and  discovered 
no  indication  of  previous  deterioration. 

Q.  Would  this  indicate  that  the  gun  had  the  proper  degree  of  tension? 
A.  I  cannot  tell  whether  or  not ;  there  was  no  ring  taken  from  this  gun. 
It  was  the  first  gun  of  that  calibre  cast,  and  was  cast  before  I  began  to 
take  rings  for  initial  strain. 

Q.  Are  not  all  the  indications  such  as  would  show  that  the  rupture 
began  on  the  top  almost  simultaneously  for  the  whole  length  of  the  gun? 
A.  I  do  not  know  that  they  are ;  the  two  pieces  into  which  the  gun 
was  broken  being  so  nearly  equal,  the  line  of  fracture  might  have  run 
forward.  I  think  it  is  highly  probable,  however,  that  nearly  the  whole 
length  of  the  longitudinal  fracture  was  made  at  the  same  time.  If  the 
shot  had  jammed  a  little  in  rear  of  the  first  cross  fracture,  the  pressure 
of  gas  would  have  been  acting  upon  the  whole  length  of  bore  behind 
that;  and  if  the  fracture  had  commenced  at  that  point  it  could,  and 
most  likely  would,  have  produced  just  such  a  fracture  as  is  shown. 

Q.  What  pressure  per  square  inch  upon  the  surface  of  the  shot, 
indented  as  in  the  report,  would  be  the  least  which  could  cause  the  in- 
dentation or  marks  referred  to  in  the  report  by  Colonel  Bagler  ? 
A.  I  could  not  tell  you  that. 

Q.  Do  you  know  the  limit  of  pressure  upon  the  square  inch  of 
surface  for  metals  rubbing  together  at  which  lubrication  ceases  to  be 
advantageous  ? 

A.  No,  I  do  not.  It  would  be  different  in  different  metals ;  and  it 
ceases  to  be  advantageous  whenever  the  pressure  is  so  great  as  to  cause 
the  interlocking  of  the  particles  of  the  rubbing  surfaces. 

Q.  If  the  pressure  were  greater  than  the  limit  referred  to  considerable 
friction  would  result  as  the  shot  was  sliding  along  the  bore  ? 
A.  Yes ;  a  great  amount  of  friction  would  be  the  result. 
Q.  Might  not  this  friction  account  for  the  reduced  velocity  of  the  shot? 
You  will  notice  round  405  had  40,000  pounds'  pressure  and  1,208  feet 
velocity,  while  the  last  round,  at  which  the  gun  burst,  No.  472,  with  the 
same  pressure,  gave  only  990  feet  velocity. 

A.  Yes ;  to  some  extent.     Suppose  the  shot  had  jammed  at  say  £  to 
Eep.  No.  266 6 


82  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

§  of  the  distance  from  the  bottom  of  the  bore  to  the  muzzle,  and  the 
gun  burst ;  then  the  shot  would  leave  with  the  velocity  which  it  had  at 
that  point.  Whatever  friction  existed  tended  to  diminish  the  velocity 
of  the  shot. 

Q.  Might  not  this  friction  so  heat  the  interior  of  the  gun  as  to  cause 
increased  tension  tangentially  sufficient  to  cause  the  rupture? 

A.  No,  I  think  not  5  it  has  not  time  to  act  before  the  shot  is  gone. 

Q.  Would  not  the  increased  tension,  by  bending  the  staves  outward 
at  the  ends,  have  the  tendency  to  cause  the  fracture  through  the  breech  ? 

A.  Yes  ;  though  I  think  not  to  any  appreciable  extent.  Where  a  con- 
siderable length  of  bore  is  acted  upon  by  the  gas  the  whole  stave  is  car- 
ried out  bodily,  except  at  the  extremities ;  but  only  so  far  as  the  tan- 
gential resistance  or  extension  of  the  metal  will  permit  them  to  go,  the 
stave  resistance  being  of  no  appreciable  value  beyond,  say,  five  calibres 
in  length. 

Q.  Has  this  gun  the  increased  thickness  through  the  breech  you  have 
previously  referred  to  in  answer  to  a  question,  and  which  you  believed 
would  have  a  tendency  to  prevent  breaking  through  the  breech  ? 

A.  My  recollection  is  that  the  gun  had  a  thickness  in  the  breech  of 
something  over  a  calibre  and  a  half,  which  experiment  has  shown,  with 
small  cylinders,  to  be  about  as  much  thickness  as  was  valuable,  there 
being  very  little  increased  resistance  from  greater  thickness. 

Q.  Do  you  now,  in  view  of  the  results  of  that  experiment,  propose  to 
still  further  strengthen  the  breech  of  the  gun  ? 

A.  No,  I  think  not,  unless  we  should  find  that  guns  break  generally 
in  such  a  manner  as  to  indicate  that  the  breech  is  too  thin. 

Q.  Will  you  examine  the  record  of  the  12-inch  hollow-cast  gun,  called 
the  Atwater  gun,  which  burst  at  Fort  Monroe  on  the  llth  of  January, 
1866,  and  inform  us  if  it  did  not  break  through  the  breech  1 

A.  The  data  here  given  is  not  sufficient  to  form  a  correct  idea ;  from 
the  report  I  should  think  it  probably  did. 

Q.  Did  the  8-inch  Eodman  rifle  which  burst  December  4,  1865,  burst 
through  the  breech  ? 

A.  I  do  not  know.  This  report  does  not  state  whether  the  gun  broke 
through  the  breech  or  not. 

Q.  What  was  the  nature  of  the  rupture  of  the  8-inch  Kodman  rifle 
which  burst  on  the  3d  of  January,  at  the  86th  round  ? 

A.  My  recollection  is  that  that  gun  burst  at  eighty-odd  fires  j  that 
gun  was  made  for  grooved  projectiles  exclusively.  We  found  that  in 
firing  with  equal  charges  of  powder  and  equal  weights  of  projectile  the 
pressure-gauge  indicated,  almost  invariably,  a  greater  pressure  behind 
the  grooved  projectile  than  behind  the  expanding  one.  The  initial 
velocity  of  the  grooved  projectile  was  generally  a  little  less  than  that  of 
the  expanding  projectile.  I  do  not  know  the  nature  of  the  fracture. 

Q.  Will  you  examine  this  record  relating  to  the  13-inch  Eodman  gun 
which  burst  July  27,  1864,  and  state  if  the  gun  did  not  rupture  through 
the  breech? 

A.  That  gun  broke  through  the  breech,  as  shown  in  this  report.  I 
have  not  examined  the  fragments  of  the  gun. 

Q.  Was  not  this  gun  made  after  the  latest  improved  model? 

A.  I  believe  it  was. 

Q.  What  was  the  thickness  of  the  iron  at  the  breech  ? 

A.  I  think  it  was  about  the  same  proportion  as  other  guns  of  my 
model  j  that  is,  about  a  calibre  and  a  half  thick. 

Q.  What  was  the  tensile  strength  of  the  iron  of  which  the  gun  was 
made  ? 

A.  1  do  not  remember. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  83 

Q.  To  what  extent  did  the  tensions  due  to  the  rate  of  cooling  from 
within  add  to  the  ability  of  this  gun  to  restrain  a  pressure  from  within  ? 

A.  I  cannot  tell  you  to  what  extent ;  there  was  no  ring  taken  from 
that  gun,  either. 

Q.  Suppose  this  gun  had  been  cast  parallel  with  its  largest  diameter 
and  closed  with  a  similar  breech  at  both  ends,  what  pressure  per  inch  of 
water  should  it  have  borne  without  breaking,  on  the  supposition  that  all 
the  parts  of  the  wall  were  brought  to  the  breaking  strain  at  the  same 
instant  ? 

A.  If  the  pressure  should  act  along  the  whole  length  of  the  gun,  you 
would  have  none  but  the  tangential  resistance  to  overcome ;  and  if  the 
entire  thickness  of  the  walls  should  be  brought  into  play,  or  to  their 
breaking  strain  at  the  same  instant,  the  interior  pressure  required  to 
burst  it  would  be  about  64,000  pounds  to  the  square  inch. 

Q.  Do  you  notice  that  shot  No.  735  has  the  pressure  recorded  of 
180,000  pounds  per  inch;  is  that  the  pressure  recorded  by  the  Rodman 
instrument  ? 

A.  I  presume  it  is ;  I  do  not  know  certainly. 

Q.  Is  that  instant  pressure,  or  is  it  momentum  I 

A.  It  is  mainly  pressure ;  there  is  a  small  amount  of  momentum,  not 
enough,  as  I  believe,  to  materially  affect  the  indications  of  pressure;  it 
may  vary,  in  a  pressure  of  that  magnitude,  as  much  as  5,000  pounds  to 
the  square  inch.  It  is  not  claimed  for  this  instrument  that  it  gives  abso- 
lutely and  accurately  the  pressure  of  the  gas  in  the  gun,  but  it  is  claimed 
that  it  is  a  valuable  guide  to  artillerists  and  gives  indications  of  pressure 
sufficiently  accurate  for  practical  purposes. 

Q.  Do  the  indications  of  pressure  given  by  the  Eodman  instrument 
resemble  the  results  got  by  Colonel  Bomford's  experiments  in  firing  a 
steel  ball  from  a  hole  drilled  in  the  side  of  the  gun  ? 

A.  No;  that  depends  upon  a  different  principle.  Colonel  Bomford 
inferred  the  pressure  of  gas  on  the  gun  from  the  number  of  thin  pieces 
of  pine  which  a  pistol  ball  thrown  by  the  gas  of  the  gun  would  penetrate. 
The  ball  in  that  barrel,  placed  behind  the  seat  of  the  shot,  and  where  the 
maximum  pressure  is  always  found,  was  so  light  that  it  was  thrown  out 
before  the  full  pressure  of  gas  in  the  gun  had  been  developed,  and  thus 
indicated  a  less  pressure  than  actually  existed. 

Q.  Do  you  think  there  is  any  difference  in  the  pressure  between  that 
which  acts  upon  the  bottom  of  the  bore  or  the  top  ? 

A.  In  the  gun  that  has  windage  of  considerable  magnitude  the  pres- 
sure on  the  top  will  be  a  little  less  than  that  on  the  bottom,  but  not 
materially  so. 

Q.  Is  there  equal  pressure  to  the  square  inch  against  the  rear  of  the 
projectile  and  against  the  bottom  of  the  bore  or  chamber? 

A.  No;  there  is  a  little  more  against  the  bottom  of  the  bore,  else  the 
gas  would  not  move  from  it — the  gas  would  move  towards  that  point 
where  the  least  pressure  is  found. 

Q.  As  the  shot  moves  forward  towards  the  muzzle,  is  the  pressure 
reduced  on  account  of  the  increased  space  into  which  the  gases  have 
expanded  ? 

A.  Undoubtedly  it  is. 

Q.  As  the  pressure  is  reduced  against  the  rear  of  the  shot,  is  it  also 
reduced  as  against  the  bottom  of  the  bore  or  chamber  f 

-A.  Certainly  it  is. 

Q.  Are  the  indications  of  the  internal  pressure  instrument  equal  to  the 
indications  of  an  external  instrument  and  inserted  in  a  hole  drilled  through 
the  side  of  the  gun  ? 


84  EXPERIMENTS  ON  HEAVY  ORDNANCE.    , 

A.  There  has  always  been  found,  where  the  two  were  used  together,  a 
slight  difference,  the  outer  one  being  a  little  greater.  The  difference  is 
supposed  to  result  from  the  presence  of  the  internal  pressure  gauge  in 
the  powder,  thus  retarding  the  rate  of  inflammation  of  the  charge  ;  the 
momentum  of  the  gas  that  strikes  against  the  piston  in  either  case  is 
very  trifling. 

Q.  Have  you  ever  had  indications  from  the  external  instrument  of 
higher  pressures  at  two  calibres  from  the  bottom  than  at  the  bottom 
of  the  bore  ? 

A.  There  is  no  such  case  that  I  now  remember. 

Q.  Most  of  the  tables  of  pressures  in  your  book  are  means  for  a  num- 
ber of  rounds,  are  they? 

A.  Yes ;  they  are  generally  so. 

Q.  When  the  external  instrument  indicates  the  highest  pressures,  the 
shot  has  begun  to  move  and  has  left  its  original  position,  has  it- not i 

A.  Yes ;  it  must  have  moved  from  its  original  position  before  the  gas 
has  reached  its  maximum  pressure. 

Q.  At  that  period  of  time,  is  the  pressure  against  the  piston  of  the 
instrument  against  the  rear  of  the  shot  and  against  the  bottom  of  the 
bore  the  same  ? 

A.  They  are  nearly  the  same;  there  would  be  in  theory  a  little  greater 
pressure  against  the  bottom  of  the  bore  than  against  either  the  shot  or 
the  instrument  ;  but  not  perceptible  in  practice. 

Q.  Suppose  there  was  another  instrument  inserted  at  the  bottom  at 
that  instant;  would  it  also  indicate  the  same  pressure  as  the  other 
instrument  ? 

A.  Yes ;  in  practice  it  would. 

Q.  On  page  176  of  your  book  is  a  table  of  pressures  at  different  points 
along  the  bore;  at  bottom — a  mean  of  three  fires  with  coarse  powder — 
you  have  10,000  pounds;  at  two  calibres  from  bottom,  26,001  pounds, 
pressure.  Can  you  account  for  this  incongruity,  except  upon  the  theory 
that  the  hole  in  the  side  of  the  gun  was  obstructed  by  the  grains  of 
powder  at  the  bottom  and  not  obstructed  at  two  calibres! 

A.  That  may  possibly  have  been  the  case.     I  know  of  no  other. 

Q.  How  can  you  account  for  the  other  incongruity,  that  at  14  calibres 
the  pressure  was  greater  than  at  12? 

A.  In  this  way:  these  are  indications  that  were  made  on  disks  of  cop- 
per. It  is  believed  to  be  due  to  the  vibration  of  the  metal  in  the  gun 
after  the  shot  has  left  striking  the  knife  edge  into  the  copper  disk.  If 
placed  in  a  thin  walled  gun,  towards  the  muzzle,  it  would  be  found  to 
be  almost  invariably  the  case  that  one  could  see  th  emarks  of  the  indent- 
ing tool  in  the  copper,  showing  that  it  had  struck  quite  a  number  of 
times,  and  that  it  had  thus  increased  the  (length  of)  cut  in  the  copper 
which  indicates  the  pressure. 

Q.  Were  all  the  holes  drilled  at  right  angles  to  the  axis  of  the  bore, 
or  was  the  hole  at  14  calibres  inclined  forward  ? 

A.  My  recollection  is  that  they  were  all  right  angles  to  the  axis  of 
the  bore. 

Q.  Have  you  ever  noticed  any  indication  of  the  instrument  which 
would  lead  to  the  conclusion  that  projectile  force  is  what  you  measure 
instead  of  pressure? 

A.  No,  I  have  not. 

Q.  Is  it  not  the  pressure  of  the  powder  which  ejects  the  shot  from  the 
gun  and  gives  it  its  velocity? 

A.  The  pressure  evolved  from  the  powder  does  it. 

Q.  How  is  it  that  there  is  so  little  difference  in  velocity  to  the  shot, 


EXPEEIMENTS  ON  HEAVY  OKDNANCE.  85 

while  the  pressures  from  the  same  powder,  in  the  same  gun,  vary  from 
8,000  pounds  pressure  to  180,000 pounds? 

A.  The  small  differences  of  the  pressure  are,  to  my  mind,  most  readily 
explained  on  the  supposition  that  the  charge  is  not  ignited  at  each  dis- 
charge in  the  same  manner.  A  primer  that  only  succeeded  in  igniting  a 
single  grain  or  so  at  a  single  point,  will  not  give  such  pressure  as  a 
stronger  primer  that  darts  its  volume  of  flame  clear  through  the  charge 
of  powder ;  the  origin  of  ignition  being  a  point,  in  one  instance,  and  a 
cone  running  through  the  entire  charge  in  the  other.  These  extraordi- 
nary differences  that  are  found,  I  believe  to  be  due  to  the  irregular  action 
of  the  projectile,  the  wedging,  or  jamming,  or  breaking,  of  the  shot  in 
the  bore,  for  I  do  not  see  how  the  knife  edge  can  be  driven  into  the  cop- 
per without  pressure,  nor  how  pressure  can  exist  in  the  bore  of  the  gun 
without  forcing  the  knife  edge  into  the  copper. 

Q.  Was  the  model  of  the  Kodman  gun  based  upon  the  indications  of 
this  instrument  ? 

A.  My  recollection  is  that  it  was  so  in  part. 

Q.  Would  the  steel  ball  fired  from  Colonel  Bomford's  experimental  gun 
have  had  higher  velocity  at  two  calibres  from  the  bottom  if  a  musket 
barrel  had  been  inserted  in  the  hole  in  the  side  of  the  gun  to  increase 
its  length,  and  the  time  of  action  of  the  pressure  ? 

A.  Undoubtedly  it  would. 

Q.  On  page  197  you  have  a  table  showing  pressures  at  different  points 
along  the  bore  in  guns  of  three  different  calibres,  7-inch,  9-inch,  and 
11-inch,  showing  the  velocity  of  the  shot  due  to  equal  columns  of  powder, 
behind  equal  columns  of  metal.  If  the  pressures  had  been  greater  in 
one  of  these  guns  under  such  circumstances  the  velocities  would  have 
been  greater,  yet  the  <•  velocity  is  remarkably  alike  from  the  three  guns 
for  a  mean  of  ten  fires,  while  the  mean  pressure  is  three  times  as  great 
in  the  11-inch  gun  as  in  the  7-inch,  and  twice  as  great  in  the  9-inch  as  in 
the  7-inch.  How  do  you  account  for  that  ? 

A.  I  do  not  know  that  I  can  account  for  it.  The  only  explanation  that 
I  can  see  applicable  to  it  is  that  the  powder  is  more  rapidly  inflamed  in 
a  large  than  in  a  small  calibre ;  this  would  give  increased  maximum 
pressure  of  gas  without  materially  increasing  the  velocity  of  the  shot. 

Q.  Has  the  length  of  the  hole,  from  the  axis  outward,  in  which  the 
pressure  instrument  is  inserted,  which  is  greater  in  the  11-inch  gun 
because  of  the  greater  thickness  of  wall,  nothing  to  do  with  it  ? 

A.  I  do  not  think  it  has,  not  to  any  appreciable  extent. 

Q.  Have  any  smooth-bores  of  large  calibre  burst  when  fired  with  solid 
shot  ? 

A.  None  except  one  13-inch,  by  experiment,  of  my  model. 

Q.  What  is  the  cause  of  the  bursting  of  the  experimental  gun  made 
upon  your  model,  of  which  you  speak? 

A.  It  was  worn  out,  having  burst  at  the  738th  fire ;  the  pressures  of 
the  last  five  rounds,  with  55  pounds  of  No.  5  powder,  were  152,000 
pounds,  170,000,  180,000,  200,000,  and  160,000  pounds  per  square  inch. 

Q.  Does  solid  shot  jam  in  the  bore  of  a  gun? 

A.  They  may  do  so  if  made  of  very  soft  iron  and  fired  with  very  quick 
powder.  Rifle  shot  are  more  liable  to  upset  than  round  shot. 

Q.  What  was  the  character  of  the  fracture  in  these  guns  which  burst? 

A.  That  of  the  13-inch  gun  before  referred  to. 

Q.  What  is  the  usual  character  of  the  fractures  of  solid  cast  guns  that 
have  burst  when  fired  with  solid  shot? 

A.  Very  much  the  same,  as  far  as  I  have  observed,  as  shown  in  my 
printed  reports. 


86  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Q.  What  is  your  theory  to  account  for  the  bursting"? 

A.  That  they  have  an  adverse  initial  strain  where  the  metal  is  good. 

Q.  Where  a  gun  burst  from  the  jamming  of  a  shell  in  the  bore,  is  the 
pressure  indicated  by  your  instrument  largely  increased*? 

A.  Certainly  if  the  gun  has  not  been  previously  injured. 

Q.  I  observe  that  the  12-inch  rifle  which  burst  at  Fort  Monroe  endured 
a  pressure  of  62,000  pounds  without  bursting  or  apparent  injury  to  the 
gun,  while  it  afterwards  burst  under  a  pressure  of  about  49,000  pounds. 

A.  I  can  only  account  for  that  on  the  supposition  that  the  large  press- 
ure and  previous  service  to  which  it  had  been  previously  subjected  had 
weakened  the  gun,  so  that  this  pressure  of  49,000  pounds  being  continued 
by  the  jamming  of  the  shot  for  an  unusual  length  of  time,  burst  the  gun. 

Q.  Is  it  your  opinion  that  the  explosion  of  a  sfyell  just  within  the  muz- 
zle of  a  gun  would  rupture  it? 

A.  It  would  depend  entirely  upon  the  circumstances  of  the  bursting 
of  the  shell  and  the  strength  of  the  gun  at  thaj  point;  the  tendency  would 
be  to  unduly  increase  the  strain  upon  the  gun ;  it  might  or  might  not 
break  it. 

Q.  Do  you  think  that  a  gun  strained  at  one  fire  by  a  pressure  to  nearly 
the  breaking  point,  will  burst  with  a  less  pressure  at  a  subsequent  fire? 

A.  Yes ;  continued  firing  with  a  less  pressure  will  burst  it,  and  it  may 
be  at  a  very  few  rounds. 

Q.  Then  the  fact  that  a  gun  may  endure  great  pressure  at  one  fire  is 
no  indication  that  it  will  endure  a  subsequent  fire  ? 

A.  No;  and  hence  it  is  that  we  have  abandoned  the  old  method  of 
proving  with  double  charges.  A  gun  has  so  much  work  or  endurance 
in  it;  it  wears  out,  like  anything  else. 

Q.  Why  have  no  experiments  been  made  to  ascertain  the  exact  effect 
of  such  casualties  upon  the  guns  ? 

A.  I  cannot  give  any  other  reason  than  that  there  has  -not  been  time 
for  it  as  yet.  That  is  owing  to  obstacles  of  one  nature  or  another  interven- 
ing to  prevent  it.  There  has  been  much  done  towards  perfecting  ord- 
nance, and  there  is  still  much  to  do. 

Q.  Have  you  ever  estimated  the  amount  of  work  exerted  on  the  entire 
bore  of  a  gun,  with  a  tendency  to  rupture  it,  for  each  degree  the  bore  is 
increased  in  temperature  ? 

A.  No ;  I  have  not. 

Q.  If  the  force  of  the  powder  alone  was  nearly  sufficient  to  burst  the 
gun,  would  not  the  addition  of  a  small  amount  of  expansive  force  be 
enough  to  rupture  it  ? 

A.  It  might  do  so  if  the  initial  strain  on  the  gun  was  too  great,  but 
would  not  do  so  where  the  initial  strain  is  too  small ;  the  expansion  of 
the  interior  of  the  gun  from  heat  in  firing  being  advantageous  to  guns 
having  too  little  initial  strain,  and  injurious  to  those  having  too  much ; 
and  the  expansion  of  the  interior,  due  to  the  heat  from  firing,  should  be 
taken  into  the  account  in  fixing  the  initial  strain  upon  the  gun,  and  a 
margin  left  for  its  action — that  is,  the  initial  strain  should  be  so  great  as 
to  bring  the  interior  and  the  exterior  to  the  breaking  point  simultaneously 
under  the  addition  of  external  strain  that  should  be  imparted  by  heating 
the  interior  in  firing  the  gun. 

Q.  What  is  the  greatest  endurance,  by  number  of  rounds,  any  8-inch 
Rodman  rifles  have  endured  ? 

A.  But  two  8-inch  Rodman  rifles  have  been  fired  to  extremity ;  the 
best  one  endured  1,047  and  the  other,  I  believe,  80  rounds — the  latter 
being  fired  with  grooved  projectiles. 

Q.  Do  you  know  anything  about  the  endurance  of  the  Ames  gun, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.         *   87 

made  of  wrought  iron,  as  compared  with  the  8-inch  Rodman,  as  relates  to 
the  average  amount  of  work  stored  up  in  projectiles  of  each  from  an 
equal  number  of  the  best  examples  of  each  kind  of  gun  ? 

A.  A  7-inch  wrought-iron  gun  made  by  Mr.  Ames,  was  fired,  I  think, 
about  700  rounds  as  a  7-inch  gun,  and  was  then  reamed  out  to  8  inches, 
and  fired  24  rounds  as  an  8-inch  gun,  when  it  burst. 

Q.  Was  that  the  best  example  of  the  Ames  system  of  guns,  as  to 
endurance  ? 

A.  Yes ;  of  14  other  gu,ns  (7-inch)  offered,  two  burst  in  the  proof,  one 
at  the  first  and  the  other  at  the  eighth  round. 

Q.  Is  that  the  one  fired  at  Bridgeport? 

A.  Yes ;  the  one  that  burst  at  the  724th  fire  is. 

Q.  What  was  the  size  of  the  charges  ? 

A.  I  do  not  know  the  size  of  the  charges.  I  have  examined  the  frac- 
ture of  this  gun.  I  folind  two  or  three  quite  deep  fissures  on  the  interior 
of  the  bore;  and  that  on  the  fractured  surface,  which  was  transverse, 
the  breech  blowing  off,  there  was  a  surface,  I  should  say,  four  inches 
wide  and  12  to  16  inches  long,  in  which  the  weld  was  so  slight  as  not  to 
amount  to  a  weld  at  all. 

Q.  I  see  by  a  report  that  a  board  of  officers  have  recommended  the 
purchase  of  10  20-inch  guns,  190 15-inch,  600 13-inch  guns,  all  smooth-bore; 
200  12-inch,  610  10-inch  guns,  rifles,  for  the  armament  of  the  fortifica- 
tions, which  requisition  has  been  approved  by  the  Chief  of  Ordnance.  Do 
you  think  that  past  experience  with  guns  of  these  calibres,  either  rifles 
or  smooth-bores,  warrants  the  purchase  of  them  for  use  in  forts  or  on 
ship-board  without  further  and  more  thorough  experiments,  and  without 
the  discovery  of  some  means  to  make  their  endurance  more  reliable  ? 

A.  My  impression  is  that  the  Chief  of  Ordnance  did  not  approve  the 
requisition  as  to  heavy  rifle  guns  referred  to  in  your  question.  It  is  a 
question  of  public  econcmy  as  to  whether  a  nation  should  arm  with  cast- 
iron  guns,  known  to  be  reliable  for  a  certain  number  of  rounds.,  or  go  to 
the  expense  of  building  up  guns,  or  making  steel  guns  that  might  stand 
a  greater  number  of  rounds.  My  belief  is  that  for  the  present  our  cast- 
iron  guns  will  do  a  given  amount  of  service  for  less  money  than  any  other 
gun  you  can  get;  for  rifle  guns,  I  do  not  know  that  cast  iron  will  so  com- 
pare with  steel  guns  or  with  built-up  guns,  as  made  in  England,  as  to 
justify  their  adoption  without  further  trial.  My  belief  is  that  no  nation 
has  yet  decided  definitely  upon  what  is  the  best  material  for  rifle  guns, 
taking  into  account  their  cost  as  compared  with  others.  Experimental 
rifle  guns  have  been  recommended  by  the  ordnance  board  and  approved 
by  the  Chief  of  Ordnance,  and,  I  believe,  by  the  Secretary  of  War.  It  is 
contemplated  that  experiments  with  them  shall  be  made  before  the  pur- 
chase of  any  large  number  of  rifle  guns  for  service,  and  the  Chief  of  Ord- 
nance so  recommended  in  his  annual  report  of  1867. 

Q.  Do  you  intend  to  say  that  the  experiments  with  Eodman  guns,  both 
smooth-bore  and  rifle,  in  service  and  in  experimental  firing,  has  demon- 
strated with  any  certainty  what  endurances  can  be  predicted  for  any 
given  gun  ? 

A.  I  do. 

Q.  Could  you  now  predict  a  certain  endurance  for  the  12-inch  gun 
recently  fired  at  Fort  Delaware  ! 

A.  I  could  not,  for  the  reason  that  I  know  that  that  gun  has  been 
unduly  strained,  and  I  do  not  know  to  what  extent. 

Q.  I  mean  only,  in  speaking  of  predicting  a  certainty  of  endurance, 
that  all  contingencies  to  accidents  liable  to  occur  shall  be  taken  into 
consideration  I 


88   *         EXPEEIMENTS  ON  HEAVY  ORDNANCE. 

A.  My  belief  is  that  after  we  shall  have  procured  a  projectile  that  is 
as  certain  in  its  operation  in  the  rifle  gun  as  the  round  shot  is  in  the 
smooth-bore,  that  we  can,  by  firing  to  extremity  one  or  two  12-inch  guns, 
fix  a  limit  within  which  the  gun  may  be  considered  as  absolutely  safe, 
but  it  will  require  experiment  to  fix  that  limit. 

Q.  Why  do  guns  of  smaller  calibre  have  so  much  greater  endurance 
than  guns  of  larger  calibre  ? 

A.  For  the  reason  that  the  pressure  of  gas  upon  them  is  less  per  square 
inch.  , 

Q.  Do  you  not  increase  the  strength  of  the  gun  in  proportion  to  the 
increase  in  the  pressure  of  the  gas  I 

A.  No ;  it  is  not  expedient  to  do  so.  We  adopted  a  different  course 
to  meet  this  difficulty ;  we  used  a  slower  burning  powder,  which  should 
give  a  less  maximum  strain  upon  the  gun,  and  a  greater  terminal  strain 
than  could  be  obtained  with  quick  burning  powder ;  and  increase  the 
length  of  the  bore  of  the  large  guns,  so  that  under  the  more  uniform 
action  of  the  gas  over  a  longer  distance,  and  during  a  longer  space  of 
time,  we  impart  to  the  projectile  velocities  nearly  if  not  equal  to  those 
obtained  in  smaller  guns,  with  powder  heretofore  used  in  them;  and,  in 
fact,  we  now  secure  greater  velocities  from  a  15-inch  gun  than  we  for- 
merly did  from  10-inch. 

Q.  If  the  restraining  force  in  a  large  gun  is  increased  in  proportion  to 
the  increase  of  force  to  be  restrained,  as  your  reply  would  indicate,  then 
why  is  the  large  more  liable  to  break  than  the  small  one! 

A.  With  the  charge  and  kind  of  powder  that  we  use  in  a  large  gun,  I 
do  not  think  it  is  more  likely  to  break,  other  things  being  equal.  It  is 
more  difficult  to  get  a  perfectly  safe  projectile  for  a  large  gun  than  for  a 
small  one. 

Q.  Could  you  not  so  increase  the  thickness  of  the  walls  of  the  gun,  and 
thus  increase  its  restraining  power,  as  to  allow  for  the  jamming  or  friction 
of  the  projectile  ? 

A.  I  have  no  doubt  that  that  might  be  done  to  a  greater  or  less  extent, 
by  the  hollow  mode  of  cooling.  A  10-inch  gun,  two  calibres  thick,  cast 
solid,  will  not,  in  my  opinion,  be  as  strong  as  a  gun  one  calibre  thick, 
owing  to  the  adverse  initial  strain  imparted  to  it  from  the  external 
cooling. 

Q.  Do  you  assign  any  other  cause  for  rupturing  of  guns  besides  the 
premature  explosion  of  shells  and  the  wedging  of  projectiles  ? 

A.  I  do  not  think  of  any  other,  except  a  variation  or  want  of  regularity 
in  the  quality  of  the  powder  used,  or  the  existence  of  adverse  or  im- 
proper initial  strain  in  them.  I  regard  the  subject  of  powder  as  of  equal 
importance  in  the  endurance  of  guns  with  the  strength  of  the  gun  itself. 

Q.  Please  read  the  following  paragraph  in  the  report  of  the  Chief  of 
Ordnance  of  the  navy,  as  to  the  knowledge  or  lack  of  knowledge  pos- 
sessed by  the  navy  on  the  subject  of  ordnance,  and  say  if  any  more 
knowledge  is  in  your  opinion  possessed  by  the  ordnance  department  of 
the  army  ? 

A.  In  my  judgment,  we  do  know  that  the  main  portion  of  our  arma- 
ment of  the  forts  ought  to  be  smooth-bore  guns,  rather  than  rifles;  the 
living  force  imparted  to  a  shot  by  our  largest  smooth-bore  guns  cannot 
be  with  equal  safety  imparted  to  a  rifle  shot.  The  accuracy  of  15-inch 
and  20-inch  guns  is,  in  my  judgment,  equal  to  that  of  any  rifle  we  have 
at  the  distance  of  2,000  yards,  and  that  of  20-inch  guns,  especially,  at 
greater  distance.  I  think  we  do  know  that  more  reliable  guns  can  be 
made  of  cast-iron  than  of  wrought,  intended  to  be  in  one  piece,  in  the 
present  state  of  the  art  of  forging.  I  would  also  state,  that  if  I  were 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  89 

going  to  remodel  our  heavy  guns,  I  should  make  them  heavier  than  they 
now  are,  our  present  model  havdng  been  fixed  in  reference  to  the  gun- 
carriages  on  hand  for  10  inch  guns;  for  15  and  20-inch  I  should  increase 
the  weight,  I  think,  certainly  25  per  cent.;  not  only  for  the  purpose  of 
giving  strength  to  the  gun,  but  to  diminish  the  injurious  effects  of  the 
recoil  upon  the  carriage  and  the  platforms.  I  think  experiments  on 
powder,  with  a  view  to  determine  the  best  form  in  which  to  place  it, 
ought  to  be  made,  as  well  as  experiments  continued  on  guns,  for  the  pur- 
pose of  determining  the  safe  endurance  of  those  we  have  on  hand,  and 
the  proper  material,  models  and  forms  of  guns,  for  their  respective 
projectiles. 

Q.  In  a  report  made  by  yourself  in  1857,  wTien  a  captain  of  ordnance, 
you  make  a  statement  in  regard  to  important  things  connected  with  gun- 
making,  of  which  you  possess  no  positive  knowledge.  Have  your  subse- 
quent experiences  thrown  any  light  upon  this  question  I 

A.  They  have.  I  have  no  doubt  now  that  the  strongest  cast-iron, 
having  the  greatest  elasticity,  hardness,  and  extensibility,  when  cast 
into  a  gun,  cooled  from  the  interior,  as  they  are  now  cooled,  will  make 
the  best  gun.  I  have  no  doubt  either,  now,  as  to  whether  guns  should 
be  cast  solid  or  hollow,  being  satisfied  that  they  should  be  cast  hollow. 
I  also  feel  satisfied  that  we  know  more  about  the  proper  model  of  a  gun 
than  we  did  at  the  time,  that  report  was  written ;  we  know  better  how 
to  determine  the  model  of  a  gun  for  a  given  weight  of  metal  and  diame- 
ter of  bore.  We  do  know  with  sufficient  accuracy  for  practical  purposes, 
the  statical  pressure  due  to  a  given  wei'ght  of  powder  and  shot.  We  have 
also  acquired  knowledge  as  to  the  effect  in  endurance  of  the  rapid  appli- 
cation of  charges  exerting  different  degrees  of  strain  upon  the  gun.  We 
have  also  acquired  knowledge  as  to  the  proper  constitution  of  the  charge 
to  produce  a  given  velocity  of  shot,  with  a  minimum  strain  upon  the  gun. 

JANUARY  28, 1869. 

Bear-Admiral  JOHN  A.  DAHLGREN  sworn  and  examined. 
By  the  CHAIRMAN  : 

1.  Question.  State  when  you  took  charge  of  the  Ordnance  Bureau  of 
the  Navy  Department. 

Answer.  In  April,  1861,  the  command  of  the  navy  yard  at  Washing- 
ton devolved  upon  me,  all  the  other  officers  having  deserted  it.  In  July, 
1862,  I  was  directed  to  take  command  of  the  Bureau  of  Ordnance  by  the 
Secretary  of  the  Navy.  In  July,  1863,  I  was  assigned  to  the  command 
of  the  South  Atlantic  blockading  squadron.  In  June,  1865,  I  returned 
north,  and  the  war  of  the  rebellion  being  closed,  I  was  detached  from 
the  squadron  which  I  commanded.  In  December,  1866, 1  took  command 
of  the  South  Pacific  squadron.  In  August,  1868,  I  was  detached  from 
the  command  of  that  squadron,  and  ordered  by  the  department  to  take 
charge  of  the  Bureau  of  Ordnance. 

2.  Q.  Have  you  given  especial  attention  to  the  subject  of  the  fabrica- 
tion of  guns  ! 

A.  I  have;  and  I  believe  there  are  very  few  officers  of  our  navy  who 
have  had  as  much  experience  as  I  have  had. 

3.  Q.  Are  you  the  inventor  of  a  system  of  gun-making,  or  the  designer 
of  a  model  for  guns  ? 

A.  I  am  the  inventor  of  a  system  of  armament  for  our  navy  generally, 
including  the  guns  and  carriages  to  be  used  in  it;  also  of  a  system  of 
naval  light  artillery,  including  carriages  and  appliances.  The  character 


I 
90  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

and  some  of  the  services  of  this  ordnance  may  be  noted  from  the  opinions 
of  distinguished  officers  immediately  at  hand,  viz : 
Admiral  Dupont  says : 

But,  besides  this,  I  am  impelled  by  a  feeling  of  duty  to  address  you.  The  large  ordnance 
of  this  squadron  has  sprung  from  your  inventive  genius  ;  and  thankful  am  I  for  one  for 
those  long  years  of  study,  scientific  research  and  deductions  which  have  so  materially  aided 
in  arming  the  American  navy  as  I  believe  no  other  navy  is  armed. 

Do  you  remember  after  I  came  from  China  my  writing  you  how  much  I  thought  of  the 
^Minnesota's  gun  deck  battery,  (9-inches. )  In  your  reply  you  modestly  seemed  to  think 
their  days  were  numbered.  I  only  now  wish  you  could  have  seen  the  practice  from  this  ship 
during  the  engagement,  not  alone  for  its  precision  and  destructive  results,  but  for  the  rapid- 
ity with  which  such  large  guns  could  be  loaded  with  their  heavy  shell.  I  never  get  trans- 
portS,  as  the  French  term  it,  about  such  things,  but  I  will  repeat,  to  the  day  of  my  death, 
that  the  second  assault  of  this  ship  upon  the  forts  for  rapidity,  continuity,  and  precision  of 
fire  has  not  been  surpassed  in  naval  warfare. — Extract  from  letter  of  November  24,  1861. 

Commodore  Bodgers  says : 

I  saw  the  terrible  effect  of  the  Wabash  battery  at  Port  Royal ;  it  was  so  rapid  in  its  fire 
that  the  rebels  on  shore  reported  in  their  papers  that  the  Wabash  was  twice  on  fire ;  it  was 
merely  the  flames  coming  out  from  her  batteries.  I  took  a  powerful  spyglass  and  looked 
through  it,  and  saw  the  shells  falling  at  a  rate  that  perfectly  astonished  me ;  so  that  nothing 
could  live  there.  The  men  were  driven  away  from  their  guns. —  Testimony  before,  the  Com- 
mittee on  Conduct  of  the  War — Heavy  Ordnance,  p.  80. 

Assistant  Secretary  Fox  says  : 

The  best  shell-gun  is  Admiral  Dahlgreii's  nine  and  eleven-inch  guns. —  Testimony 
before  Committee  on  Conduct  of  the  War — Heavy  Ordnance,  p  170. 

Commodore  Alden  says  : 

Question.  What  number  and  calibre  of  guns  had  you  on  board  the  Brooklyn  in  your  expe- 
dition against  Fort  Fisher?  -Answer.  We  had  twenty  9-inch  guns,  two  10!J-po under  Par- 
rotts,  and  two  60-pounder  Parrotts — all  four  of  the  Parrotts  rifled. 

Q.  How  many  times  were  those  guns  fired  in  the  two  attacks  upon  the  fort? — A.  I  threw 
into  that  fort  3,40..;  nine-inch  shells,  over  120  tons. 

Q.  How  did  the  guns  bear  that  shelling? — A.  As  soon  as  I  heard  of  the  100-pounder 
bursting,  I  put  mine  on  the  opposite  side  of  the  ship  from  that  with  which  I  was  fighting, 
and  put  in  their  places  the  nine-inch  guns,  so  that  I  had  12  nine-inch  guns  in  battery  all  the 
time. 

Q.  Then  you  did  not  use  those  100-pounder  Parrotts  ? — A.  Not  after  I  heard  of  the  acci- 
dents with  them  on  the  other  ships.  I  never  fired  them  again. 

Q.  Were  those  nine-inch  guns  made  on  the  Rodman  principle? — A.  They  were  Dahlgren 
guns. 

Q.  Were  they  cast  hollow  or  otherwise  ? — A.  They  were  the  Dahlgren  nine-inch  guns  ;  the 
best  gun  ever  made. 

Q.  What  effect  had  that  firing  upon  them  ? — A.  I  never  discovered  that  any  of  them  were 
injured. 

Q.  Did  none  of  them  fail  ? — A.  Not  in  the  slightest  degree.  The  men  stand  around  them 
and  fight  with  them  with  as  much  confidence  as  they  drink  their  grog.  * 

—  Testimony  before  the  Committee  on  Conduct  of  the  War — Heavy  Ordnance,  p.  172. 

Captain  Wise,  Chief  of  Bureau  of  Ordnance,  says : 

During  the  recent  rebellion  the  cast-iron,  smooth-bore  guns  of  the  navy  endured  all  the 
severe  service  to  which  they  were  subjected,  and  proved  their  excellence  everywhere  and 
under  all  conditions  of  actual  war.  Not  a  single  gun  of  the  Dahlgren  system  has  burst 
prematurely.  *  *  * 

While  the  practice  at  the  test  battery  against  armor  plating  shows  that  even  the  1 1-inch  at 
close  quarters  is  capable  of  piercing  any  thickness  of  iron  or  steel  with  which  the  sides  of  an 
ordinary  cruiser,  intended  to  keep  the  seas,  could  be  covered  with  safety,  and  this  without 
any  danger  of  rupture  from  the  use  of  increased  charges,  unless  the  gun  has  been  very  much 
weakened  by  previous  service.  *  *  * 

— Annual  report  to  Niivy  Department,  November,  1865. 

Vice- Admiral  Porter  says : 

The  gun  which  I  deem  best  adapted  to  general  use  in  the  navy  is  the  11-inch  gun,  which 
can  be  carried  on  board  even  our  smallest  vessels,  worked  in  a  sea  way,  if  the  vessels  are 
properly  constructed,  and  almost  as  rapidly  as  a  34-pounder;  at  all  events  rapidly  enough 
for  all  practical  purposes. 

I  consider  its  accuracy  much  greater  than  any  rifle  gun,  or  any  gun  of  a  smaller  calibre. 
That,  I  believe,  has  been  tested  to  the  satisfaction  of  most  navy  officers. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  91 


I  remember  once  on  an  occasion  having  used  30  pounds  of  powder,  when  the  service 
charge  was  only  15.  You  may  remember  that  I  drew  the  attention  of  the  bureau  to  this  at 
the  time.  Some  thought  that  I  was  giving  the  gun  more  powder  than  it  would  stand.  I 
recollect  on  the  above  occasion  I  attained  great  range,  and  prevented  myself  from  being 
annoyed  by  some'rebel  gunboats  provided  with  small  rifle  guns  of  considemble  range.  See- 
ing the  great  range  obtained  with  my  11-inch  gun,  they  let  me  alone.  I  could  not  follow 

them,  as  there  was  a  bar  between  us. 

******** 

That  most  important  power,  ricochet  firing,  is  entirely  lost  in  the  rifle  guns ;  and  in  a 
sea  way  a  vessel  armed  with  11-inch  guns  is,  in  my  opinion,  a  match  for  a  vessel  with  twice 

the  number  of  rifle  guns. 

******** 

I  have  never  to  my  knowledge  known  an  accident  happen  to  the  9-inch,  10-inch,  or  11-inch 
guns,  three  of  the  best  guns  we  ever  had  in  our  navy ;  and  in  battle  men  stand  behind  these 

guns  in  perfect  security,  knowing  that  the  chances  of  their  bursting  are  very  small. 

*  ***  *  *  *  * 

Against  wooden  vessels  nothing  is  equal  to  11  inch  guns,  and  I  believe  that  a  small  and 
fast  vessel  that  could  choose  her  distance,  carrying  a  couple  of  1  Much  guns,  could 
damage  seriously,  if  not  drive  off,  the  largest  ship  in  the  British  navy  armed  as  they  were  in 
1861.  I  believe,  moreover,  that  an  11-inch  gun,  firing  a  solid  steel  ball,  would  smash  in  the 
Bides  of  some  of  the  heaviest  English  iron  clads,  and  would  damage  very  seriously  the 
turrets  of  some  of  our  heaviest  vessels  — Extract  from  letter,  January  15,  1SG9. 

4.  Q.  What  is  the  method  of  the  fabrication  of  a  gun  of  large  calibre 
in  your  system? 

A.  The  largest  calibre  which  I  proposed  to  use  in  wooden  vessels  is 
the  11-inch  gun.  At  that  time  there  were  no  iron-clads  in  existence. 
The  casting  of  the  gun  was  to  be  solid — nearly  of  equal  diameters,  and 
tapering  from  the  breech  to  the  chase,  nearly  the  diameter  of  the  gun  at 
the  breech,  but  very  much  smaller  than  the  diameters  of  the  finished  gun 
at  the  chase;  the  object  being  to  produce  as  much  uniformity  in  cooling 
as  is  desired.  This  casting  was  afterwards  to  be  turned  down  to  the 
dimensions  required  for  the  gun,  preferring  to  leave  the  skin  of  the  cast- 
ing on  the  cylinder  and  the  breech  of  the  gun,  which,  however,  was  not 
always  done. 

5.  Q.  From  your  experience,  what  do  you  consider  to  be  the  relative 
endurance  of  guns  cast  solid,  of  the  model  described,  as  compared  with 
guns  cast  hollow,  on  the  system  of  General  Eodman1? 

A.  We  have  the  practical  results  of  a  large  number  of  guns  cast  for 
the  navy  in  the  way  that  1  have  described — smooth-bores  of  9  and  11- 
inch  calibre;  they  have  withstood  all  the  tests  of  battle  during  the  war 
of  the  rebellion,  1  believe,  with  hardly  an  exception.  These  cannon 
have  done  all  the  service  that  was  required  of  them;  were  used  in  almost 
all  our  actions ;  in  the  great  battles  of  Dupont,  Farragut,  Porter,  &c. 
Many  of  the  11-inch  have  been  frequently  fired  with  charges  very  much 
above  those  designed  for  them,  viz,  15  pounds,  which  is  all  that  was 
really  necessary  for  eifect  against  the  strongest  wooden  vessel.  Being 
suddenly  brought  into  the  war  of  the  rebellion,  and  being  compelled  to 
use  these  guns  against  iron  plating,  heavier  charges  were  frequently 
resorted  to.  I  may  refer  to  the  action  at  Mobile,  where  Admiral  Far- 
ragut hauled  up  alongside  the  rebel  ram  Tennessee;  he  used  much 
heavier  than  the  ordinary  charges.  I  have  myself  fired  11-inch  guns 
in  experimenting  at  iron  plating  with  solid  shot  and  30  pounds  of  powder, 
which  w^as  mo?e  than  double  the  strain  that  the  gun  was  intended  to 
stand.  One  of  them  was  fired  in  this  way  about  200  times  and  did  not 
burst.  I  think,  therefore,  that  it  can  be  said  that  the  form  of  my  guns 
and  the  method  of  casting  them  are  fully  equal  to  every  requirement  of 
the  severest  service.  The  history  of  the  past  shows  no  endurance  of 
other  cannon  equal  to  that  of  the  9  and  11-inch  guns.  Nothing  has  been 
more  common  in  the  great  naval  actions  of  the  European  naval  powers 


92  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

than  the  bursting  of  cannon  and  the  loss  of  life  consequent  thereon. 
The  records  of  our  own  navy  are  not  without  such  accidents.  In  the 
celebrated  fight  of  Paul  Jones  with  the  British  frigate  Serapis,  some  of 
his  lower  deck  guns  burst,  "  bio  wing  up  the  deck  above  and  killing  or 
wounding  a  large  proportion  of  the  people  that  were  stationed  below. 
This  disaster  caused  all  the  guns  to  be  instantly  deserted,  for  the  men 
had  no  longer  confidence  in  their  metal.  It  at  once  reduced  the  broadside 
of  the  Richard  to  about  a  third  less  than  that  of  her  opponent,  not  to 
include  the  disadvantage  of  the  manner  in  which  the  force  that  remained 
was  distributed  amon  g  light  guns.  In  short,  the  combat  was  now  between 
a  12-pounder  and  anl8-pounder  frigate." — Cooper's  Naval  History,  p.  106. 
I  have  no  doubt  that  the  same  method  of  casting  and  fabricating  the 
9  and  ll-inoh  guns  could  be  used  in  making  the  largest  calibres;  but  to 
do  so  it  will  be  necessary  to  obtain  a  competent  knowledge  of  the  kinds 
of  iron  that  are  to  be  used  in  the  foundries  for  this  purpose. 

6.  Q.  Have  smoothbore  guns  cast  upon  your  system,  with  like  charges, 
manifested  greater  endurance  and  serviceability  than  guns  of  like  calibre 
cast  according  to  the  system  of  General  Eodman  ? 

A.  I  believe  that  guns  of  8  and  10-inch  calibres  as  well  as  of  15-inch 
have  been  cast  hollow  upon  the  plan  of  General  Eodman,  but  they  have 
never  been  proved  to  the  extent  that  solid-cast  guns  of  11-inch  calibre 
have  been  proved ;  therefore,  we  do  not  positively  know  how  great  their 
endurance  really  is.  The  endurance  of  a  few  guns  cast  with  special 
care  under  the  superintendence  of  General  Eodman  is  not  to  my  mind 
complete  evidence  of  the  endurance  of  a  large  number  of  guns  of  the 
same  kind  cast  at  different  foundries  and  taking  the  chances  of  the  expe- 
rience or  want  of  experience  of  different  founders  and  of  various  kinds 
of  iron. 

7.  Q.  If  you  were  now  to  re-arm  the  navy  would  you  do  so  with  guns 
cast  solid  or  hollow  ? 

A.  If  the  guns  were  to  be  11-inch,  or  of  that  weight,  say  16,000  to 
20,000  pounds,  most  certainly  they  should  be  cast  solid,  as  they  have 
always  been  ;  if  above  that  weight,  then  I  should  proceed  to  experiment 
with  different  kinds  of  iron,  in  the  full  belief  that  I  should  be  as  success- 
ful with  these  heavy  guns  as  with  the  11-inch.  The  first  trials  of  cast- 
ing hollow  guns  of  heavy  calibre,  by  General  Eodman,  took  place  in 
1849  and  1851.  Six  guns  were  cast,  three  hollow  and  three  solid,  in 
pairs.  Each  hollow-cast  gun  endured  a  larger  number  of  rounds  than 
its  fellow  cast  solid.  In  all  cases  the  solid  guns  were  so  bad  that  the 
comparison  only  proves  that  two  of  the  hollow-cast  guns  were  better 
than  very  bad  guns  that  had  been  cast  solid.  Considering  the  hollow- 
cast  guns  by  themselves,  it  will  be  seen  that  two  out  of  the  three  were 
bad — almost  as  bad  as  they  could  be,  their  endurance  being  so  low.  Only 
one  of  the  three  proved  to  be  a  good  gun ;  it  withstood  1,500  rounds, 
and  was  not  burst ;  but  every  ordnance  officer  knows  that  it  is  not  the 
excessive  endurance  of  one,  or  of  a  few  pieces,  that  gives  character  and 
confidence  to  a  lot  of  guns  5  it  is  the  uniform  endurance  of  the  whole, 
even  if  that  be  not  very  high ;  because  it  is  the  unforeseen  bursting  of 
the  gun  that  does  the  mischief  in  action.  When  General  Eodman's  hol- 
low-cast guns  did  attain  a  good  degree  of  uniformity  it  was  with  an 
entirely  different  model ;  and  that  model  I  claim  as  my  own,  and  havef 
so  apprised  the  War  Department.  With  this  new  model  General  Eod- 
man made  two  10-inch  guns,  putting  them  to  an  extreme  proof,  which 
they  endured  to  the  extent  of  4,082  rounds  without  bursting.  The  solid 
gun  was  more  indented  at  the  seat  of  the  shot  than  the  hollow  gun  ;  but  I 
think  this  to  be  of  little  consequence,  because,  in  practice,  a  gun  of 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  93 

heavy  calibre  would  be  laid  aside  long  before  it  reached  4,000  rounds. 
I  think  the  conclusions  from  these  data  are :  1st.  That  when  the  hollow 
casting  was  used  with  the  columbiad  of  old  model  it  failed  to  make  them 
uniformly  good.  2d.  When  the  columbiad  was  shaped  after  my  model 
the  guns  were  as  good  when  cast  solid  as  hollow.  I  think  the  whole 
question  of  rifled  guns  is  open ;  I  do  not  think  that  anything  is  known 
about  it,  either  in  wrought  or  cast  iron.  I  know  of  nothing  in  foreign 
countries  in  which  I  believe  they  have  really  reached  better  results  than 
we  have  here.  But  a  few  days  since  I  observed  in  the  newspapers  that 
one  of  the  English  guns  that  they  had  relied  on  so  much  had  given  way, 
(the  Fraser  gun.) 

8.  Q.  Have  experiments  in  this  country  demonstrated,  as  yet,  that 
large  rifle  guns  can  be  made  according  to  the  Rodman  system  with  a 
reasonable  certainty  of  endurance  ? 

A.  I  think  not. 

9.  Q.  How  will  it  compare  in  rifles  with  the  solid  mode  of  casting? 
A.  The  solid  casting  has  given  no  better  results  with  rifled  cannon 

than  the  hollow. 

10.  Q.  What  is  your  opinion  as  to  the  correctness  of  the  Eodnian 
theory  of  gun-making  ? 

A.  At  first  sight  it  seems  to  be  well  founded ;  but  I  think  that  a  full 
consideration  would  show  that  it  is  quite  as  open  to  objection  as  any 
other,  and  even  more  so.  Some  of  my  opinions  on  this  subject  will  be 
found  more  at  length  in  a  paper  annnexed,  marked  note  A. 

11.  Q.  Has  this  system  ever  been  adopted  in  the  navy  ? 

A.  Only  in  the  casting  of  15-inch  guns.  That  was  done  under  very 
peculiar  circumstances.  The  Navy  Department  had  ordered  15-inch  guns 
to  be  put  into  the  first  monitors.  At  that  time  we  had  no  iron-clads,  and 
the  rebels  had  suddenly  precipitated  one  upon  our  blockading  squadron 
at  Hampton  roads,  destroyed  two  frigates,  threatened  to  break  up  the 
blockade  there,  and  the  plan  of  the  campaign  which  was  just  about  to 
move  under  General  McClellan  down  the  Chesapeake  against  Eichmond. 
The  rebels  were  known  to  have  iron-clads  in  readiness  at  other  places. 
There  was  no  time  for  experimenting  with  the  15-inch  cannon ;  it  only 
remained  for  us  to  do  the  best  we  could.  There  had  been  but  one  gun  of 
the  kind  made  at  that  time;  it  had  been  cast  hollow,  and  had  endured 
a  proof  of  about  500  fires,  but  with  inferior  charges;  when,  therefore,  I 
sent  the  draught  for  the  navy  15-inch  gun  to  the  bureau,  I  advised  the 
bureau  to  have  those  guns  made  exactly  as  the  first  15-inch  gun  had  been 
.made,  the  hollow  casting  included,  until  there  was  time  for  experi- 
ments wTith  other  methods. 

12.  Q.  With  what  description  of  guns  is  the  navy  now  provided;  that 
is,  as  to  methods  of  manufacture? 

A.  The  heavy  guns  of  the  navy  are  the  smooth  9,  10,  11-inch  guns,  all 
of  my  own  system,  and  cast  solid;  the  navy  15-inch,  cast  hollow,  and 
the  Parrott  100-pounder  rifle  cannon.  The  150-pounders  have  been  with- 
drawn from  the  naval  service.  (See  note  B.) 

13.  Q.  Have    you  any  other   rifled  guns   besides  the  100-pounder 
Parrotts  1 

A.  No  other.  Opinion  has  very  much  changed  in  our  navy  since  the 
beginning  of  the  war  of  the  rebellion  as  regards  the  value  of  rifled  guns. 
Then  the  demand  was  incessant.  The  idea  seemed  to  be  prevalent  that 
smooth-bore  cannon  could  not  be  pitted  against  rifle  cannon  under  any 
circumstances.  I  think  that  sentiment  is  very  much  changed.  My  own 
experience,  from  repeated  action,  induces  me  to  give  preference  to  heavy 
smooth-bore  guns.  I  always  thought  that  they  hurt  our  iron-clads  more 


94  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

in  battle  than  the  rifles  did,  and  I  am  inclined  to  believe  that  the  same 
opinion  prevails  largely  in  the  navy,  independently  of  the  distrust  of  the 
rifle  guns  which  we  now  have. 

14.  Q.  Have  not  these  changes  in  the  views  entertained  in  the  navy 
with  respect  to  rifles  been  largely  owing  to  their  unreliability  f 

A.  I  think  they  have ;  but  independently  of  this  I  have  seen  instances 
where  the  power  of  the  11-inch  and  the  rifled  150-pounder  were  in  direct 
contrast.  A  number  of  officers  and  men  witnessed  the  practice  at  long 
range  of  both.  1  allude  more  particularly  to  a  case  in  battering  a  work 
on  the  Stono  river. 

15.  Q.  Were  not  the  Parrott  rifles  condemned  by  the  board  of  ordnance 
officers u? 

A.  The  150-pounders  were  recommended  to  be  withdrawn  by  a  board, 
which  was  done.  The  bureau  also  reduced  the  charge  of  the  100-pounder. 
(See  Report  of  Bureau,  1865.) 

16.  Q.  If  the  condemnation  extended  to  all  guns  made  by  Captain 
Parrott,  why  have  they  been  retained  in  service  f 

A.  It  did  not  extend  to  100-pounders  or  to  rifled  guns  of  less  calibre. 

17.  Q.  Do  you  think  the  100-pounders  reliable  guns  I 
A.  I  should  be  apt  to  handle  them  very  carefully. 

18.  Q,  Have  any  Parrott  guns  burst  in  the  naval  service  since  the 
conclusion 'of  the  war  ? 

A.  Yes ;  a  rifled  30  pounder  burst  recently  in  the  South  Pacific  squad- 
ron, which  I  just  left.  I  do  not  think  the  number  of  rounds  had  amounted 
to  200.  I  reported  it  to  the  Secretary  of  the  Navy,  and  told  him  we 
had  no  rifle  guns  in  the  navy  that  were  reliable,*  asking  leave  to  pro- 
ceed to  investigate  the  question  and  ascertain  if  reliable  rifle  guns  could 
be  procured. 

19  Q.  What  is  your  opinion  of  the  utility  of  guns  as  large  as  those  of 
15  and  20-inch  calibre,  as  compared  with  smaller  calibres  ! 

A.  I  was  not  of  the  opinion  that  the  15-inch  gun  was  most  suitable 
for  the  navy.  I  doubted  if  sufficient  charges  could  be  used  to  drive  a 
shot  of  that  size  with  the  required  velocity,  having  proper  regard,  first, 
to  the  endurance  of  the  gun,  and  then  to  the  endurance  of  the  carriage. 
It  is  considered  advisable  to  check  the  recoil  by  mechanical  means ;  and 
it  is  doubtful  if  they  would  long  endure  the  enormous  strain  of  very 
heavy  charges.  A  lower  calibre  than  15-inch,  with  a  higher  charge, 
might  be  sufficiently  effective  against  iron-plating.  I  was  conducting 
experiments  to  that  end  in  1863,  when  I  left  to  go  to  sea,  and  had  driven 
a  10-inch  shot  through  six  inches  of  iron  at  200  yards,  with  a  smooth- 
bore of  10  inch  calibre. 

20.  Q.  How  does  rapidity  of  fire,  other  conditions  being  equal,  affect 
the  result  of  battles,  ship  against  ship,  or  ship  against  works  on  the 
shore  ? 

A.  Of  course  the  more  rapidly  that  successive  blows  could  be  struck 
the  sooner  will  the  result  be  reached ;  but  the  safety  of  the  gun  is  to  be 
considered,  as  the  bursting  of  a  15-inch  gun  on  board  of  a  ship  would 
be  very  fatal. 

21.  Q.  What  is  the  heaviest  calibre  of  gun  compatible  with  rapidity 
of  fire  and  mounting,  in  numbers,  011  the  broadside  of  ships  I 

A.  In  my  system  of  naval  armament  I  take  the  ground  that  the 
heaviest  guns  should  be  used  which  can  be  worked  upon  the  broadside 
carriages,  and  for  pivot  guns  that  throw  the  heaviest  shot  that  can  be 
handled  at  sea ;  the  rapidity  of  fire  of  such  cannon  is  quite  sufficient 

*  This  does  not  include  our  rifle  boat-guns,  which  are  good  enough. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  95 

under  the  most  favorable  circumstances,  the  gun  not  being  trained  or 
pointed,  nor  the  elevation  changed.  An  11-iucli  gun  can  be  fired  on  a 
fixed  platform  once  a  minute ;  but  I  doubt  if  this  can  be  done  on  ship- 
board in  action ;  certainly  not  continued  for  much  time. 

22.  Q.  How  rapidly  are  15-inch  guns  in  monitor  turrets  fired  ? 

A.  My  recollection  of  that  is  not  very  clear ;  in  action  there  were 
always  other  objects  to  take  off  my  attention  $  but  so  far  as  I  do  remem- 
ber I  think  it  required  between  five  and  six  minutes  to  fire  a  shot  j  that, 
however,  included  the  revolution  of  the  turret  from  the  enemy's  battery 
and  back  again.  Moreover,  the  person  who  fired  the  gun  could  never 
see  the  object,  but  was  directed  in  his  aim  by  another  person  at  a  tube 
in  the  side  of  the  turret.  Then  there  was  time  lost  by  giving  the  word 
to  the  engineer,  who  worked  the  lever  for  turning  the  turret ;  all  this 
and  the  swaying  of  the  vessel  must  be  counted  in  the  time  of  firing. 

23.  Q.  Are  rifie  or  smooth-bore  guns  most  effective  against  iron  plat- 
ing, if  the  weight  of  the  gun  and  projectile  are  alike,  and  the  initial 
velocity  is  the  same  from  both  kinds  of  guns  ? 

A.  Supposing  shot  of  equal  weight  to  strike  with  equal  velocity, 'I 
should  prefer  the  round  shot ;  but  this  is  open  to  opinion  and  further 
experiments. 

24.  Q.  Have  any  experiments  been  made  to  ascertain  the  effect  u£on 
guns  of  the  premature  explosion  of  shells  within  their  bores  f 

A.  I  remember  trying  one  such  experiment  with  an  11-inch  gun.  1 
think  it  was  evident  in  some  cases  that  the  shell  was  not  burst  in  the 
bore  of  the  gun,  by  arrangements  that  were  made  for  the  purpose.  In 
the  other  cases  the  shell  had  burst  in  the  gun.  The  gun  was  unhurt, 
but  the  number  of  rounds  were  small — five  or  six.  Still,  I  have  a  very 
strong  doubt  if  the  bursting  of  shells  in  guns  are  the  cause  of  the 
repeated  splittings  of  the  chase  that  are  reported. 

25.  Q.  Do  you  attribute  the  rupture  of  guns  to  that  cause  if  a  gun 
gives  way  in  the  rear  of  the  trunnions  f 

A.  If  a  cannon  gives  way  in  the  rear  of  the  trunnions  it  must  be 
owing  solely  to  its  inability  to  withstand  the  charge  with  which  the  gun 
has  been  fired  j  but  a  gun  might  have  such  bad  metal  in  front  of  the 
trunnions  that  it  would  crack  from  the  bounding  of  the  projectile  in 
connection  with  the  bursting  of  the  shell.  I  have  never  seen  a  gun 
myself  that  I  thought  was  split  in  the  chase  by  the  bursting  of  shells. 

26.  Q.  How  do  you  account  for  the  blowing  off  of  the  muzzle  in  the 
15-inch  gun! 

A.  If  a  gun  had  previously  been  cracked  in  the  chase,  the  force  of  the 
charge  and  bounding  of  the  projectile  might  subsequently  be  sufficient 
to  break  the  chase  and  blow  the  pieces  in  front.  » 

27.  Q.  Does  increasing  the  thickness  of  the  wall  of  the  gun  beyond 
a  certain  limit  increase  the  strength  of  the  gun  f 

A.  I  think  not.  I  think  there  is  a  thickness  of  metal,  taken  in  con- 
nection with  the  process  of  founding,  which  will  give  a  greater  strength 
to  a  gun,  within  certain  limits  j  of  course  a  gun  might  be  made  so  extra- 
ordinarily thick  that  no  charge  could  burst  it. 

28.  Q.  Does  the  strongest  iron  always  make  the  strongest  gun  ? 

A.  There  was  an  idea  prevailed,  when  I  first  became  connected  with 
the  ordnance,  that  the  quality  of  iron  for  guns  was  invariably  indicated 
by  a  certain  degree  of  tensile  strength  and  density,  without  reference  to 
the  different  qualities  of  iron.  To  this  I  never  agreed  j  and  I  am  inclined 
to  believe  that  the  advocates  of  the  theory  are  pretty  well  satisfied  that 
it  was  not  well  founded.  I,  myself,  have  always  used  the  tension  strain 
and  density  as  measures  of  uniformity  simply  j  that  is,  when  a  good  gun 


96  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

had  been  obtained  from  any  kind  of  iron,  the  tension  strain  and  density 
of  its  metal,  in  connection  with  other  signs,  were  to  be  followed  in  other 
guns  of  the  same  class  cast  from  the  same  kind  of  iron.  The  kinds  of 
iron  differ  very  much,  and  hitherto  we  have  been  able  to  obtain  good 
guns  from  all  of  them  by  varying  the  treatment. 

29.  Q.  Are  there  any  means  of  ascertaining,  with  approximate  accu- 
racy, the  pressure  of  the  gases  of  gunpowder  on  the  bore  of  a  gun  ? 

A.  I  do  not  think  there  are.  General  Kodman  has  a  method  which 
he  relies  on,  and  which,  I  believe,  is  confided  in  by  the  War  Department. 
But  I  confess  I  never  did  rely  upon  it  as  entirely  accurate.  There  were 
experiments  tried  for  this  purpose  by  Colonel  Bomford,  very  many  years 
ago,  by  boring  a  hole  along  the  line  of  a  gun  to  measure  the  force  with 
which  the  gases  issued  from  these  apertures.  This  idea  has  often  been 
attributed  to  myself,  and  is  said  to  have  been  the  basis  of  the  form 
which  I  have  used  for  cannon ;  which  is  eKtirely  incorrect.  The  idea 
belongs  to  Colonel  Bomford,  and  the  form  of  my  cannon  are  the  results 
of  reasoning  entirely.  The  draught  of  the  first  11-inch  gun  is  the  same 
that  is  now  used.  I  never  altered  it  in  any  respect,  except  to  remove 
the  swell  of  the  muzzle  from  the  end  of  the  gun,  for  more  convenient 
use  in  the  narrow  ports  of  iron  dads. 

30.  Q.  Is  the  range  for  an  11-inch  gun,  with  light  charge,  so  nearly 
uniform  as  to  justify  the  belief  that  the  pressure  of  the  gases  of  the 
powder  is  nearly  uniform  in  the  gun  $ 

A.  I  have  no  means  of  answering  this  question  positively.  The 
ranges  of  the  11-inch  guns,  with  the  regulation  charge  of  15  pounds,  are 
very  uniform,  and  I  think  more  accurate  than  any  other  smooth-bore 
gun  of  the  same  description  and  calibre. 

31.  Q.  Have  you  ever  determined,  by  experiment,  the  ratio  of  increase 
of  the  pressure  of  gasses  of  powder  in  a  gun,  if  the  weight  of  the  pro- 
jectile is  increased1? 

A.  I  never  have,  nor  do  I  think  there  are  any  means  by  which  that 
could  be  ascertained.  We  know,  generally,  that  the  pressure  upon  a  gun 
increases  in  a  much  higher  ratio  than  the  weight  of  the  charge  of  the  pow- 
der j  that  is  to  to  say,  if  you  double  the  weight  of  the  charge  you  would 
very  much  more  than  double  the  strain  upon  the  same  gun. 

32.  Q.  Would  the  pressure  of  the  gas  evolved  from  the  powder  upon 
a  square  inch  of  the  surface  in  a  chamber  of  the  same  diameter  be  less 
or  greater  than  the  pressure  per  square  inch  in  a  large  chamber  ? 

A.  I  do  not  think  that  we  have  any  means  of  determining  these  results 
with  any  accuracy. 

33.  Q.  Have  any  experiments  been  made  to  determine  the  increase  of 
strain  upon  the*  bore  of  a  gun  by  not  having  the  shot  home  against  the 
powder  charge  ? 

A.  I  think,  many  years  ago,  that  Commodore  Stockton  made  some 
experiments  of  that  kind.  The  general  impression  is  that  there  should 
be  no  space  between  the  charge  and  the  shot,  as  it  strains  the  gun  more. 

34.  Q.  Do  you  know  the  comparative  tensile  strength  and  density  of 
the  iron  used  in  the  long  68-pounder  and  the  Dahlgren  9-inch  gun  $ 

A.  1  do  not  5  but  believe  that  the  metal  of  the  English  68-pounders 
has  always  been  inferior  to  that  of  our  9  and  11-inch  guns. 

35.  Q.  It  is  stated  that  the  tensile  strength  of  the  long  68-pounder  is 
about  18,000  pounds,  while  that  of  the  9-inch  gun  is  30,000. 

A.  The  tensile  strength  of  the  United  States  guns  varies  with  different 
irons.  We  have  had  excellent  iron  where  the  tenacity  was  25,000  pounds, 
while  the  West  Point  and  Boston  iron  was  giving  good  metal  at  30,000 
to  35,000  pounds;  but  the  English  establishment  failed  so  badly  with 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  97 

their  68-pounders  that  it  was  thought  to  have  been  one  of  the  causes  that 
led  to  the  substitution  of  a  scientific  civilian  like  Sir  William  Armstrong 
for  the  officer  in  charge  of  the  government  foundry,  a  measure  which 
worked  badly  in  all  respects,  particularly  in  cost. 

36.  Q.  What  is  the  least  tensile  strength  permitted  to  be  used  in  the 
11-inch  Dahlgren  guns? 

A.  That  would  depend  entirely  upon  the  tenacity  exhibited  by  a  good 
trial  gun.  If  such  a  gun  were  made  at  Boston,  the  iron  they  use  would 
probably  exhibit  a  higher  strength,  elsewhere  a  lower.  I  had  some  diffi- 
culty in  that  respect  with  some  of  the  15-inch  guns  that  were  made  at 
Pittsburg,  and  had  a  correspondence  with  the  founder  on  that  subject — 
he  having  varied  considerably  from  the  density  of  the  trial  gun,  which  I 
insisted  he  should  adhere  to  within  certain  limits  in  order  to  preserve 
uniformity  with  the  trial  gun. 

37.  Q.  Do  you  think  the  tensile  strength  of  the  iron  has  comparatively 
little  to  do  with  the  endurance  of  the  gun  ? 

A.  It  is  necessary  to  maintain  it  in  that  degree,  which  is  ascertained 
by  trial  to  belong  to  the  kind  of  iron  used. 

38.  Q.  How  do  you  account  for  the  apparent  anomaly  referred  to  in 
Eodinan's  book,  where  he  says  the  strongest  iron  does  not  make  the 
strongest  gun,  and  where  he  states  that  having  too  much  density 
resulted  in  reducing  the  endurance  of  the  gun? 

A.  The  iron  of  the  highest  density  does  not  always  make  the  strongest 
gun. 

39.  Q.  Will  the  charge  now  prescribed  for  the  navy  gun  give  the 
highest  attainable  velocity  to  the  shots  ? 

A.  The  regular  charges  for  the  9-inch  and  11-inch  guns  will  give  all 
the  velocity  required  to  do  the  work  for  which  these  guns  were  designed; 
that  is,  the  destruction  of  wooden  vessels.  They  will  bear  much  higher 
charges — I  should  say  one-half  higher ;  and  there  is  an  order  at  the 
bureau  authorizing  30  pounds  to  be  used  with  the  11-inch  guns  in  special 
cases. 

40.  Q.  Will  they  bear  50  pounds  of  powder? 

A.  The  carriages  would  not  very  long,  and  it  is  not  necessary  that  the 
guns  should,  for  the  purposes  for  which  they  were  made. 

41.  Q.  Will  they  endure  the  charges  necessary  to  give  the  highest 
velocity  to  the  projectile  ? 

A.  The  11-inch  can  be  safely  used  as  high  as  25  pounds,  and  even  to  30 
pounds,  which  is  double  the  charge  for  which  the  gun  was  designed. 

42.  Q.  How  do  the  highest  charges  successfully  used  in  these  guns 
compare  with  the  charges  successfully  used  in  the  Armstrong  guns  ? 

A.  I  am  not  sufficiently  informed  in  regard  to  the  Armstrong  guns  to 
answer  accurately ;  but  we  do  know  that  the  Armstrong  guns  have  been 
laid  aside,  and  that  the  9-inch  and  11-inch  guns  are  not. 

43.  Q.  You  have  said  that  a  100-pounder  is  the  only  rifle  cannon  in 
the  United  States  naval  service ;  what  is  its  ability  to  stand  heavy 
charges,  compared  with  other  rifles? 

A.  I  am  unable  to  say. 

44.  Q.  What  is  your  opinion  of  the  Ames  system  of  making  wrought- 
iron  guns?  » 

A.  It  must  be  judged  by  its  results;  they  are  before  the  committee. 

45.  Q.  Do  you  think  the  Ames  guns  are  better  guns  than  Parrott's? 
A.  Whatever  may  be  said  of  the  merits  or  demerits  of  the  Parrott  gun, 

or  the  necessity  for  superseding  it,  no  other  rifle  gun  has  yet  obtained 
sufficient  confidence  to  take  its  place. 
Rep.  No.  266 7 


98  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

NOTE  A. 
[Despatch  No.  576.  ] 

FLAG  STEAMER  PHILADELPHIA, 
Port  Royal  Harbor,  #.  (7.,  November  20,  1864. 

SIR  :  I  have  received  but  a  few  days  since  a  communication  from  the 
Bureau  of  Ordnance  in  relation  to  the  casting  of  cannon  of  my  design. 

The  nature  of  the  recommendations  therein  made  by  the  bureau  to  the 
department  seems  to  render  it  proper  that  I  should  address  the  depart- 
ment directly. 

The  unceasing  demands  on  my  time  and  attention  absolutely  render  it 
impossible  for  me  to  reply  to  this  communication  as  I  would  wish, 
nor  have  I  the  documents  at  hand,  if  I  had  the  leisure  to  use  them. 
I  am,  therefore,  obliged  to  content  myself  with  the  following  incomplete 
expression  of  my  views : 

The  9-inch  and  11-inch  guns  of  my  design  have  manifested  all  the  en- 
durance that  has  been  required  through  a  course  of  trial  on  the  proving 
ground,  and  through  a  course  of  service  which  has  seldom,  if  ever,  been 
applied  to  any  other  cannon. 

The  endurance  has  never  been  approached  previously  by  such  heavy 
calibres,  and  it  has  also  been  uniform,  which  is  absolutely  indispensable 
to  give  value  to  any  endurance,  for  it  is  the  unexpected  bursting  of  can- 
non that  does  the  mischief. 

In  trials  made  to  test  the  strength  of  the  9-inch  and  11-inch  no  gun 
has  ever  fallen  short  of  1,500  rounds  when  fired  with  the  charges  for 
which  the  cannon  was  intended,  and  I  feel  no  doubt  that  if  the  firing  had 
been  continued  with  service  charges,  the  guns  tried  would  have  gone  to 
2,000  or  2,500  rounds. 

This  was  never  done,  because  no  probable  exigency  would  ever  have 
made  such  a  demand  on  a  single  gun  5  extreme  charges  were  therefore 
substituted.  Some  of  the  cannon  that  have  been  so  tested  were  at  the 
Washington  navy  yard,  and  unless  removed  are  there  still. 

One  of  them,  a  9-inch  gun,  was  fired  1,500  times  with  service  charges, 
and  still  looks  well  5  another  was  fired  1,500  times,  and  then  with  increas- 
ing charges,  until  at  the  22d  of  such  fires  there  were  20  pounds  of  powder 
and  90  pounds  of  shot  in  the  gun  when  it  gave  way. 

Many  other  cases  of  severe  proof  are  recorded  of  the  9-inch  guns. 

The  first  11-inch  gun  was  fired  more  than  1,300  times  with  shell,  and 
about  650  times  with  solid  shot  of  170  pounds ;  it  burst  at  the  1,959th 
round  fire.  Other  11-inch  guns  have  been  submitted  to  severe  tests.  One 
was  used  for  practice  against  iron  plates  with  solid  shot,  and  charges 
increasing  to  30  pounds,  to  the  extent  of  200  fires,  and  was  in  good  order 
when  I  left  it. 

It  is  to  be  borne  in  mind  that  these  guns  were  not  intended  to  be  fired 
with  solid  shot,  and  that  previous  to  their  advent  800  rounds  were 
looked  on  as  a  fair  standard  for  heavy  guns,  such  as  columbiads. 

In  actual  service  the  record  of  the  9-inch  and  11-inch  guns  is  unex- 
ceptionable. 

They  have  constituted  the  armament  of  our  principal  ships  of  war  for 
10  years. 

They  have  been  carried  over  the  whole  globe  during  more  peaceable 
times  in  those  superb  ships  Wabash,  Minnesota,  &c.,  and  now  that 
rebellion  and  disloyalty  threaten  the  Union,  they  are  identified  with  the 
greatest  glories  of  the  flag. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  99 

Admiral  Stringham,  at  Hatteras ;  DuPont,  at  Port  Royal  j  Farragut, 
at  New  Orleans  and  Mobile,  illustrated  their  power  against  forts  and 
batteries,  while  the  Kearsarge  vindicated  the  principles  of  my  system 
generally  against  the  matured  conclusions  of  British  authorities. 

Hundreds  of  these  guns  have  been  cast  and  carried  by  vessels  second 
to  none  of  their  class  ;  in  no  one  instance  has  a  single  9-inch  or  11-inch 
cannon  been  burst  on  shipboard  or  a  man  hurt.  One  or  two  were  split 
at  the  extreme  end  near  the  muzzle,  but  this  could  only  have  arisen  from 
improper  loading,  and  the  guns  were  still  capable  of  being  used  with 
effect  and  safety.  No  officer  hesitates  to  place  confidence  in  his  9-inch 
or  11-inch  guns,  and  Admiral  Farragut  when  engaging  the  Tennessee 
shotted  his  9-inch  shell  guns  with  one-third  more  powder  than  the  usual 
charges,  and  he  was  not  mistaken,  at  least  in  their  endurance. 

These  guns  were,  in  the  strictest  sense,  shell-guns.  They  were  designed 
15  years  ago,  when  wooden  vessels  only  wore  to  be  the  objects  of 
fire,  and  it  was  this  extensive  application  of  the  shell  power  that  caused 
resort  to  iron  plating  to  keep  them  out. 

But  so  great  was  the  strength  which  9  inch  and  11-inch  guns  proved  to 
have,  that  no  hesitation  existed  in  loading  them  with  shot  and  higher 
charges  of  powder  for  battering  even  iron  plating,  and  the  11-inch  guns 
did  good  service  to  the  country  on  more  than  one  such  occasion. 

When  the  rebel  rani  Merrimack  issued  forth  and  inflicted  such  griev- 
ous damage  at  Hampton  Eoads,  she  was  driven  back  by  the  Monitor's 
two  11-inch  guns,  and  never  ventured  on  another  trial. 

There  was  a  deal  of  wise  discussion  at  the  time  about  penetration 
and  wrought-iron  shot,  &c. ;  but  the  simple  and  undisputed  fact  remained. 
The  Merrimac  was  obliged  to  endure  the  blockade  of  the  Monitor,  and 
never  dared  to  venture  to  the  conflict  5  her  commander  preferred  to  sink 
her,  and  did  so. 

At  Mobile  the  few  brief  moments  of  opportunity  were  so  aptly  used 
by  the  rapid  fire  of  the  11-inch  guns  of  the  Chickasaw  that  the  iron- 
clad Tennessee  yielded  to  their  blows,  when  neither  the  tremendous 
shocks  of  the  steamers  nor  the  sluggish  fire  of  the  15-inch  gun  had 
been  able  to  accomplish  the  desired  result.  In  the  end  they  might  have 
done  so,  but  in  battle,  time  is  just  as  essential  to  success  as  in  other 
things.  Here  it  is  notorious  that  the  rapid  and  sustained  fire  of  the 
11- inch  cannon  of  the  Ironsides  was  more  dreaded  by  the  rebels  than 
the  15-inch  guns  of  the  monitors,  and  while  she  remained  here  attracted 
the  chief  efforts  of  the  rebels  to  blow  her  up. 

If,  then,  so  many  important  and  undisputed  facts  have  established  the 
endurance  of  these  guns,  while  their  origin,  use,  and  association  with 
events  have  imparted  to  them  a  reputation  so  entirely  naval,  why  pro- 
pose any  change  in  their  manufacture  ? 

They  have  faithfully  withstood  every  ordeal,  and  are  now  identified 
with  the  fame  of  the  navy  in  this  great  struggle  of  the  country  to  main- 
tain its  very  existence. 

What  public  interest  demands  it,  if  all  that  has  been  proposed  or 
required  in  the  use  of  the  guns  has  been  accomplished  ? 

Change  of  itself  is  not  improvement,  and  it  cannot  in  this  instance 
be  made  without  additional  expense  to  the  treasury. 

One  cent  per  pound  is  seemingly  no  great  expenditure,  but  in  each 
gun  itself  it  amounts  to  one,  two,  or  even  four  hundred  dollars,  and  when 
cannon  must  be  made  by  hundreds  the  sum  becomes  important. 

But  the  recommendation  is  not  merely  to  substitute  hollow  castings 
for  solid,  or  to  exercise  a  sound  discretion  at  any  time  upon  the  subject, 
for  the  15-inch  guns  of  the  navy  designed  by  myself  are  cast  hollow, 


100          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

according  to  Major  Eodman's  plan  of  casting;  the  proposition  is  to  use 
no  other  mode  of  casting  but  Major  Eodman's,  and  to  bind  the  bureau 
itself  from  using  any  other. 

Why  do  this"?  Why  voluntarily  impose  a  restraint  when  none  is 
needed?  Is  there  any  apprehension  that  the  asserted  superiority  of  the 
hollow  casting  might  suffer  from  competition1? 

No  opinion  is  given  in  the  documents  of  the  bureau  from  Mr.  Chaffee, 
the  manager  of  the  Providence  Works;  I  should  have  liked  to  know 
his  opinion ;  and  the  letter  of  Seyfert  and  McManus  is  by  no  means  a 
testimonial  to  the  merits  of  the  hollow  castings. 

The  paper  of  Mr.  Parrott  states  many  facts  which  are  of  interest, 
though  they  seem  to  have  escaped  the  pencilled  selection  of  some  care- 
ful hand.  I  beg  the  particular  attention  of  the  Navy  Department  to 
one  of  these  remarks. 

Mr.  Parrot  says : 

I  was  particularly  acquainted  with  the  manufacture  and  trial  of  the  navy  9  and  11-inch 
Dahlgren  guns,  cast  solid,  and  they  had  given  more  uniformly  satisfactory  results  than  the 
hollow-cast  columbiads  of  the  old  model,  to  which  the  experiments  of  Major  Rodman  were 
for  a  long  time  confined. 

It  did  not  appear  from  the  foregoing  and  other  trials  that  the  very  great  theoretical  advan- 
tages which  might  be  hoped  for  in  the  hollow  castings  were  particularly  realized.  (See 
Rodman  on  Metals  for  Casting,  &c.,  1861,  pp.  94,  96,  for  statements  of  these  advantages.) 

But  a  further  experiment  was  made  after  the  model  of  the  10-inch  columbiad  had  been 
changed,  by  rounding  off  the  angular  breech  and  giving  increased  thickness  at  the  bottom 
of  the  bore.  In  this  instance  both  the  solid  and  hollow-cast  guns  endured  well,  reaching 
4,250  rounds  each  without  bursting. 

I  think  that  what  Mr.  Parrot  here  states  admits  of  neither  question 
nor  qualification.  Please  to  note  that  the  solid-cast  11-inch  gun,  not 
with  any  special  care,  but  with  no  more  than  is  usual  in  current  manu- 
facture of  a  large  number,  gave  "more  uniformly  satisfactory  results 
than  the  hollow-cast  columbiads  of  old  model  to  which  the  experiments 
of  Major  Kodman  were  for  a  long  time  confined." 

Now  note  what  Mr.  Parrot  says  a  little  further  on : 

But  a  further  experiment  was  made  after  the  model  of  the  10-inch  columbiad  had  been 
changed  by  rounding  off  the  angular  breech,  and  giving  increased  thickness  at  the  bottom 
of  the  bore.  In  this  instance  both  solid  and  hollow-cast  guns  endured  well,  reaching  4,250 
rounds  each  without  bursting. 

The  plain  and  direct  conclusions  from  these  statements  are : 

1st.  That  when  Major  Eodman's  mode  of  hollow  casting  was  applied 
to  the  army  columbiad  of  the  old  model  my  solid-cast  11-inch  guns 
gave  more  uniformly  satisfactory  results. 

2d.  And  that  when  the  model  was  changed  there  was  obtained  a  very 
striking  advantage  to  Major  Eodman's  hollow  casting.  It  went  to  4,250 
rounds. 

This  would  have  been  a  stubborn  fact  to  overcome  by  itself,  but  it  does 
not  stand  by  itself;  for  a  gun  of  exactly  the  same  improved  model  was  cast 
from  the  same  furnace,  the  same  iron,  and  cast  solid,  as  the  \\.-inch  guns  are 
cast.  That,  too,  endured  just  the  same  amount  of  firing  as  the  hollow- 
cast,  nearly  4,250  rounds. 

Well,  from  all  this  it  follows: 

1st.  That  hollow  casting  would  not  save  a  bad  model. 

2d.  That  when  the  bad  model  was  changed  to  a  better,  the  solid-cast 
gun  endured  just  a:u  much  as  the  hollow. 

Now  I  desire  that  the  department  may  be  fully  aware  of  what  is 
implied  by  this  "rounding  off  the  angular  breech  and  giving  increased 
thickness  to  the  bottom  of  the  bore ; "  and  to  do  this  I  would  ask  that 
three  models  may  be  made  and  placed  before  you,  having  the  diameters 
at  the  base  ring  equal  in  all  three  models.  No.  1  shall  be  a  10-inch  col- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          101 

ulnbiad  of  the  old  pattern,  that  even  Major  Bodman's  hollow  castings 
would  not  save,  and  which  he  has  abandoned.  No.  2  shall  be  a  10-inch 
columbiad  of  the  pattern  to  which  it  was  changed  and  which  is  now 
used,  having  given  so  much  endurance  to  the  hollow  and  solid  castings. 
No.  3  shall  be  that  of  my  11-inch  gun. 

Let  the  eye  then  decide  how  far  the  model  of  the  11-inch  gun  departs 
from  that  of  the  old  columbiad  or  any  previous  model,  naval  or  mili- 
tary; and  how  marked  the  coincidence  of  the  new  army  10-inch  and  15- 
inch  with  the  model  of  the  11-inch,  the  latter  being  rather  longer ;  but 
in  the  disposition  of  the  metal  about  the  vital  parts  of  the  gun,  how 
close  the  resemblance.  The  appendage  for  elevating  being  a  plate  in  one 
gun  and  a  cascabel  in  the  other;  but  neither  affects  the  principle  of 
construction  that  disposes  the  mass  of  metal  about  the  bore.  My  guns 
are  chambered,  and  the  army  guns  are  not,  which  has  no  connection 
with  external  model,  but  concerns  the  bore  alone. 

The  eye  cannot  be  misled  by  any  special  arguments  developed  in 
lengthy  technical  formula  and  symbols  entirely  incomprehensible  save 
to  the  initiated  few.  To  it  the  relative  diameters  at  different  parts,  the 
character  of  the  curves  that  unite  them,  the  absence  of  projections  and 
rings,  produce  forms  as  nearly  identical  as  possible  to  vary  at  all.  The 
department  has  already  the  statements  of  Mr.  Parrott  that  the  mode  of 
hollow  casting  did  not  succeed  with  the  old  model,  but  that  it  had  suc- 
ceeded with  a  new  model ;  and  I  think  it  will  appear  from  comparison  of 
the  models  just  suggested  that  the  model  of  the  army  10-inch  and  8-inch, 
as  well  as  the  15-inch,  made  by  Major  Rodman,  is  identical  with  the 
models  of  my  9-inch  and  11-inch  guns. 

This  I  submitted  to  the  War  Department  some  two  years  ago,  and  so 
far  all  I  gained  by  a  plain  statement  has  been  some  long  arguments  by 
Major  Eodman,  in  which  he  undertakes  to  show  that  the  models  are  not 
alike,  as  if  any  statement  could  possibly  negative  the  plain  evidence  of 
one's  sight.  So  that  the  change  to  the  hollow  casting  did  not  succeed 
until  a  change  of  model  was  resorted  to,  and  this  was  an  adoption,  in 
effect,  of  the  11-inch  model. 

It  is  now  attempted  by  the  recommendation  of  the  bureau  to  take  from 
me  even  the  claim  to  the  hard  labor  of  years.  Such  a  wrong  as  this  I 
feel  assured  will  not  be  tolerated  by  the  department. 

It  has  caused  me  the  greatest  astonishment,  coming  as  it  does  from 
the  naval  Bureau  of  Ordnance,  to  which  I  might  have  looked  for  at  least 
fair  play. 

My  absence  and  present  duties  might  have  plead  for  postponement  at 
least,  no  necessity  being  shown  for  such  urgent  action.  But  if  the  recom- 
mendation must  be  made,  why  not  a  few  weeks  earlier  than  it  was  f  I 
was  in  Washington,  and  might  have  said  a  word  in  my  own  behalf. 
Why  defer  until  some  three  weeks  after  I  left,  a  proposition  involving  so 
much  to  myself,  and  then  urge  it  upon  the  department,  leaving  me  after- 
wards in  utter  ignorance  of  what  was  going  on,  until  the  department 
insists  on  knowing  what  I  have  to  say  I 

Nothing  but  the  consideration  of  the  Navy  Department  averted  the 
decision.  With  a  wise  and  sound  discretion  it  refused  to  act  hastily,  and 
until  I  had  been  heard. 

I  cannot  admit  that  we  yet  know  all  that  is  needed  to  a  full  decision 
as  to  the  mode  of  casting.  If  hollow  casting  is  better  for  any  size  of 
guns,  why  cool  it  with  water  1  Will  not  the  old  mode  of  casting  hollow, 
as  practiced  a  century,  answer  ?  Who  can  speak  of  trials  made  with 
American  material,  such  as  now  used,  and  American  experience  ? 

Mr.  Chaffee  had  the  boldness  to  cast  a  13-inch  gun  solid,  and  it  endured 
172  firings ;  this  was  considered  a  failure. 


102          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

When  the  largest  of  these  hollow-cast  columbiads  gave  way  with  per- 
haps no  better  endurance,  was  that  considered  a  failure  ?  Mr.  Chaffee 
had  never  cast  so  large  a  gun ;  he  had  never  melted  and  cooled  the  iron 
he  used  in  such  great  masses  ;  if  he  reached  the  result  he  did  at  the  first 
trial,  what  might  be  expected  by  further  experience  f 

My  own  impression  is  that  this  result  was,  under  the  circumstances, 
highly  favorable. 

In  conclusion,  I  hope  that  I  have  been  able  to  satisfy  the  department 
that  there  is  every  propriety  in  my  submitting  an  earnest  protest  against 
the  recommendations  of  the  Bureau  of  Ordnance : 

1.  It  is  needless,  because  the  9-inch  and  11-inch  guns  have  done  all 
that  has  or  should  be  required  of  them  without  failing  in  any  one  instance. 

2.  It  is  an  additional  expense  to  the  government  without  any  advantage. 

3.  It  is  unjust  to  the  hard  and  constant  labor  which  I  have  given  to 
the  subject,  and  to  the  benefit  which  the  navy  has  derived  from  these 
labors. 

4.  It  is  forbidden  by  professional  regard  for  ordnance — naval  in  its 
origin,  naval  in  its  use,  and  naval  in  its  association  with  great  results. 

I  will  only  add  my  earnest  request  that  the  department  will  give  an 
order  to  the  Bureau  of  Ordnance  that  no  change  whatever  shall  be  made 
in  the  model  or  details  of  my  9-inch  and  11-inch  guns,  and  that  they 
shall  continue  to  be  cast  and  finished  just  as  they  have  been — that  is, 
solid ;  and  that  no  change  shall  be  made  in  the  model  or  details  of  my 
new  130-pounder  (10-inch)  and  13-inch  guns. 

I  believe  it  is  supposed  by  some  that  considerable  pecuniary  advantage 
results  to  me  from  these  guns.    I  have  only  to  say  that  I  never  derived 
a  cent  from  them,  nor  asked  for  it. 
I  have  the  honor  to  be,  very  respectfully,  your  obedient  servant. 

J.  A.  DAHLGREN, 

Rear-Admiral,  Contfdg  South  Atlantic  Blockading  Squadron. 
Hon.  GIDEON  WELLES, 

Secretary  of  the  Navy. 


NOTE  B. 
[From  the  "  Ordnance  Instructions,"  United  States  navy,  1866,  page  102,  part  /.] 

Owing  to  the  recent  accidents  which  have  taken  place  with  these  guns  the  ISO-pounder  has 
been  withdrawn  from  service,  and  the  charge  of  the  100-pounders  provisionally  reduced  to  8 
pounds  of  rifle  powder,  and  the  short  shell  of  80  pounds  only  is  to  be  used. 


JANUARY  29, 1869. 
NORMAN  WIARD  recalled. 

By  the  CHAIRMAN  : 

1.  Question.  What  are  the  most  important  qualities  of  the  metals  fitting 
them  to  be  the  material  from  which  guns  are  to  be  made  ? 

Answer.  Tensile  strength,  i.  e.,  ability  to  resist  ultimate  pressure  or 
ability  to  resist  breaking  apart  against  the  extending  strain.  Permanent 
elasticity  is  next  in  importance,  which  is,  in  fact,  the  ability  to  recover 
the  original  form  and  dimensions  after  the  distorting  force  has  ceased  to 
act.  Incompressibility  is  another  important  quality,  involving  hardness 
to  resist  penetration  or  abrasion.  Ductility  is  a  quality  not  desired  in 
gun  metals,  as  it  is  seldom  accompanied  by  elasticity.  The  qualities  of 
metals  as  conductors  or  non-conductors  of  heat  should  be  considered,  as 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  103 

the  metal  for  large  guns  which  will  conduct  the  heat  slowest  from  the 
surface  of  the  bore  outward  when  being  fired  would  be  most  unequally 
heated,  other  conditions  being  equal. 

2.  Q.  What  direct  forces  act  upon  the  bore  of  the  gun,  having  the  tend- 
ency to  deteriorate  it  or  destroy  it  ? 

A.  The  elastic  force  resulting  from  the  combustion  of  gunpowder 
should  be  divided  and  considered  in  both  of  its  forms,  namely :  pressure 
that  is  inert  without  motion,  but  which  is  exerted  in  all  directions 
equally,  requiring  a  definite  strength  to  resist  its  performance  of  work, 
and  projectile  force,  or  vis  viva,  a  quality  of  force  resulting  from  the  ele- 
ments of  pressure  and  velocity,  pressure  and  distance,  or  pressure  and 
time  of  action  while  in  motion. 

3.  Q.  When  a  chamber  is  filled  with  gunpowder  and  the  powder  is 
ignited,  which  of  these  forces  act  upon  its  surface  ? 

A.  If  a  chamber  be  filled  with  grains  of  powder,  and  each  grain  be 
ignited  simultaneously,  the  gas  resulting  from  combustion  would  flow 
radially  in  all  directions  from  each  grain  as  a  centre ;  the  currents  meet- 
ing half  way  between  contiguous  grains  would  expend  nearly  all  their  pro- 
jectile force  and  motion  upon  each  other,  resulting  in  a  pressure  against  the 
walls  of  the  chamber,  but  slightly  greater  upon  each  square  inch  of  the  sur- 
face, than  would  result  in  the  same  chamber  if  the  grains  had  been  inserted 
one  at  a  time  in  succession  and  ignited,  with  the  gas  confined  until  the 
same  quantity  of  powder  had  been  burned.  If  the  chamber  were  spherical 
and  only  half  filled  with  powder  grains,  upon  the  ignition  as  before,  part 
of  the  powder  and  gases  would  be  projected  across  the  vacant  space  in 
such  various  directions  that  a  large  part  of  the  projectile  force  would  be 
expended  by  the  diverging,  converging,  and  reverberating  currents,  upon 
each  other.  The  effect  upon  the  walls  of  the  chamber  on  the  unfilled  side 
would  be,  however,  greater  than  in  the  previous  case  referred  to  with  the 
chamber  full,  though  depending  principally  upon  the  rapidity  of  com- 
bustion. If  the  chamber  contained  the  proper  quantity  of  water  to  be 
evaporated  into  steam,  and  which  created  the  same  ultimate  pressure  in 
the  chamber,  to  be  generated  by  slowly  heating  the  water,  it  is  obvious 
the  rate  of  its  projectile  force  against  the  walls  of  the  chamber  would 
but  slightly  exceed  the  forces  of  ultimate  pressure.  If  the  Kodman 
instrument.  Plates  VIII  and  IX,  relied  upon  by  the  ordnance  corps  for 
the  determination  of  the  pressure  of  powder  in  guns,  should  be  inserted 
in  the  side  of  the  chamber  while  the  pressure  of  the  steam  was  gradually 
evolved,  the  cut  in  the  copper  specimen  would  have  the  same  depth  as 
any  other  cut  in  any  other  specimen  made  by  the  application  of  a  weight 
equal  to  the  pressure,  in  pounds,  of  the  steam  against  the  piston  of  the 
instrument.  But  if  the  Eodman  instrument  should  be  applied  to  the 
chamber  upon  the  outer  end  of  a  tube  seven  inches  in  length,  having  a 
stop-valve  closed  while  the  steam  was  being  generated  to  the  pressure 
of  5,000  pounds  to  the  square  inch,  when  the  valve  was  opened  the  steam 
would  flow  along  the  tube  with  such  velocity  as  to  strike  the  piston  of 
the  instrument  with  a  projectile  force,  which  would  cause  a  penetration 
of  the  copper  specimen  so  deep  as  to  represent  a  force  of  15,850  pounds. 
If  the  length  of  the  tube  should  be  increased  from  seven  inches  to  nine 
inches,  the  projectile  force  would  be  equal  to  a  pressure  on  the  piston  of 
21,100  pounds,  and  with  11-inch  length  of  tube,  the  pressure  would  be 
equal  to  27,800  pounds  upon  the  square  inch.  These  statements  and 
figures  are  founded  upon  the  experiments  of  Eodman,  as  shown  on  page 
197  of  his  book,  (see  Appendix  D,  miscellaneous  extracts,)  the  result  of 
the  firing  guns,  each  having  a  different  thickness  of  wall,  namely,  a  7  inch 
gun  with  a  wall  about  seven  inches  thick  at  the  front  of  the  cartridge ;  a 


104          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

9-inch  gun  with  a  9-inch  wall,  and  an  11-inch  gun  with  an  11-inch  wall. 
If  it  was  pressure  of  the  powder  in  this  case  which  caused  the  velocity 
to  be  given  to  the  projectile,  it  is  most  remarkable  that  the  velocity  of 
the  shots  for  a  mean  of  10  fires  from  the  7-inch  gun,  in  which  the  powder 
exerted  a  mean  pressure,  according  to  the  indications  of  the  instrument, 
of  12,675  pounds  to  the  inch,  should  be  so  nearly  the  same  as  the  velocity 
of  the  projectile  from  the  11-inch  gun,  in  which  the  instrument  shows 
the  mean  pressure  to  have  been  36,224  pounds  to  the  square  inch,  or 
nearly  three  times  to  force  "behind  an  equal  column  of  metal.'*'  (The 
table  of  the  results  referred  to  is  shown,  Appendix  D.) 

4.  Q.  Then  you  have  the  opinion  that  the  Rodman  instrument  only 
shows  the  projectile  force  of  the  powder,  and  not  its  pressure  ? 

A.  The  deductions  drawn  by  Rodman  in  relation  to  the  pressure  exerted 
by  the  powder  upon  the  surface  of  the  bore  of  the  guns  are  very  lame 
conclusions,  yet  they  have  been  taken  as  indicating  a  proper  model  for 
guns  to  give  "the  required  strength  at  the  different  points  of  their  length, 
and  as  confirming  the  fallacious  conclusions  of  the  ordnance  corps, 
founded  upon  the  experiments  of  Colonel  Bomford  many  years  ago, 
having  for  their  object  the  determination  of  the  pressure  at  the  different 
parts  of  the  length  of  the  bore.  Colonel  Benton  says  of  these  experi- 
ments: "About  1845,  Colonel  Bomford  devised  a  plan  for  determining 
the  pressure  at  various  points  of  the  bore  by  conducting  experiments  that 
essentially  consisted  in  boring  a  series  of  small  holes  through  the  side  of 
the  guns  at  right  angles  to  its  axis,  the  first  hole  being  placed  at  the  seat 
of  the  charges,  and  the  others  at  intervals  of  one  calibre ;  a  steel  ball  was 
projected  from  each  hole  in  succession  by  the  force  of  the  charge  acting 
through  it,  and  the  pressure  at  the  various  points  was  deduced  from  the 
velocities  communicated  to  the  balls.'"  This,  and  the  common  use  of  the 
Rodman  instrument  in  all  late  experiments  by  the  ordnance  corps, 
shows  that  it  is  only  the  projectile  forces  of  the  powder  which  has  been 
considered  by  them  from  1845  to  the  present  time,  and  upon  these  falla- 
cious theories  the  models  of  our  guns  have  been  determined  and  their 
strength  fixed. 

5.  Q.  What  is  the  difference  between  the  projectile  force  and  the 
pressure  of  the  powder,  and  has  one  a  fixed  and  continuous  proportion 
to  the  other  ? 

A.  The  projectile  force  of  the  powder  is  the  force  equal  to  that  which 
would  be  developed  or  exhibited  in  stopping  the  projectile.  The  pressure 
is  that  force  which  gives  it  motion  in  the  gun,  and  it  can  be  seen  that  if 
such  a  force  as  that  acting  upon  the  projectile  should  act  against  the  sur- 
face of  the  bore  in  the  gun,  no  material  could  be  found  from  which  guns 
could  be  made  which  would  not  either  enlarge  the  bore  or  burst  as  a  gun, 
unless  it  were  from  material  which,  if  formed  into  a  plate  and  fixed  upon 
the  side  of  a  ship  as  armor,  would  resist  the  impact  of  a  shot  from  a  gun 
without  any  indentation  whatever.  When  a  wrought-iron  shot  is  fired 
from  a  gun  at  a  plate  which  it  does  not  penetrate  to  any  considerable 
depth,  the  shot  is  flattened  by  the  impact.  If  the  pressure  of  the  powder 
were  not  less  than  the  projectile  force,  the  shot  would  be  invariably  flat- 
tened to  the  same  extent  in  the  gun,  which,  however,  is  not  the  case.  I 
have  frequently  experimented  with  an  air-gun  of  one-fourth  of  an  inch  in 
diameter  of  bore.  With  a  pressure  of  750  pounds  of  air  to  the  square 
inch  in  the  receiver,  the  bullet  is  projected  with  force  enough  to  pass 
through  one  inch  thickness  of  hard  wood.  After  charging  the  gun  with 
that  pressure,  I  have  discharged  a  bullet  from  it  and  penetrated  that 
thickness  of  wood ;  then  after  inserting  another  bullet,  have  restrained 
it  from  being  ejected  from  the  barrel  by  inserting  a  steel  ramrod  down 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          105 

against  the  bullet  by  the  pressure  which  I  could  exert  with  my  hand, 
grasping  the  ramrod  where  it  protruded  from  the  muzzle  of  the  gun ; 
upon  removing  the  ramrod  the  same  bullet  previously  held  in  the  gun 
was  discharged  and  passed  through  the  wood  target.  It  is  obvious  that 
I  could  not  have  forced  the  ramrod  through  one  inch  of  hard  wood  by 
any  pressure  that  I  exert  by  my  hand  under  such  circumstances.  In  fact, 
I  found  that  I  could  scarcely  make  a  perceptible  indentation  in  the  wood 
by  a  pressure  on  the  ramrod  equal  to  that  which  I  had  exerted  while 
restraining  the  bullet  in  the  gun. 

6.  Q.  Are  the  indicated  pressures  shown  by  the  Eodman  instrument 
uniform  under  like  circumstances  9 

A.  They  are  not ;  on  many  occasions,  with  equal  charge  of  powder 
and  equal  weight  of  projectile  in  the  same  gun,  the  results  have  been 
widely  different — they  are  quite  as  incongruous  as  would  be  the  penetra- 
tion of  a  shot  from  the  same  gun  projected  against  iron  armor,  if  the 
shot  should  sometimes  strike  fair,  and  at  various  other  times  ricochet  once, 
or  ofteiier,  from  intervening  ground  between  the  gun  and  target  or  meet 
obstructions  to  its  flight  previous  to  hitting  the  plate. 

7.  Q.  What  is  the  cause  of  the  uncertainty  of  the  instrument? 

A.  The  currents  of  gas  projected  against  the  piston  of  the  instrument 
are  obstructed  sometimes  by  the  intervening  grains  of  the  unburnt  pow- 
der. They  may  be  reflected  or  diverted  from  the  straight  line  of  direction, 
thus  expending  their  projectile  force,  or  part  of  it,  against  other  surfaces, 
in  which  case  of  course  the  instrument  could  not  record  the  full  projectile 
force. 

8.  Q.  Is  it  only  the  projectile  force  of  the  gases  of  powder  which  causes 
the  penetration  of  the  specimen  with  the  Eodman  instrument  ? 

A.  No ;  there  is  also  the  projectile  force  of  the  piston  and  moving  parts 
of  the  instrument  itself,  (see  figure  2,  plate  IX,)  which  adds  greatly  to  the 
force  as  it  is  recorded,  so  that  under  no  circumstances  whatever  could 
the  instrument  fail  to  show  a  force  much  greater  than  the  direct  pressure 
of  the  powder  as  exerted  to  enlarge  the  bore  or  burst  the  gun.  So  called 
pressures  have  been  indicated  by  the  instrument  on  the  15-inch  gun 
with  55  pounds  of  powder,  as  low  as  10,000  pounds  to  the  square  inch, 
and  indications  from  11,000  to  13,000  pounds  are  quite  common  in  the 
reports ;  it  is  quite  impossible,  considering  the  momentum  of  the  piston 
and  moving  parts  of  the  instrument,  but  that  these  lowest  pressures  are 
greater  than  the  real  pressure  exerted  by  the  gases  of  the  powder  on  the 
gun  under  any  circumstances.  In  one  report  I  find  a  pressure  as  recorded 
of  13,000  pounds  giving  an  initial  velocity  to  the  shot  of  1,441  feet  per 
second,  and  on  another  page  of  the  same  report  another  pressure  of  98,000 
pounds,  in  the  same  gun,  giving  only  a  velocity  of  1,240  feet  per  second 
with  an  equal  charge. 

9.  Q.  Is  it  possible  to  avoid  having  the  projectile  force  of  the  gases  of 
the  powder  act  upon  the  surface  of  the  bore  in  the  gun  ? 

A.  It  is  only  necessary,  in  order  to  prevent  the  projectile  force  acting 
to  an  injurious  extent,  that  the  chamber  should  be  full,  whether  the 
powder  be  coarse  or  fine,  or  whether  it  burns  quick  or  slow ;  the  ultimate 
pressure  would  be  nearly  the  same,  if  the  powder  is  composed  of  the  same 
elements  equally  incorporated.  The  projectile  force  with  which  the 
gases  of  the  powder  expand,  if  unrestrained  even  for  a  short  length  of 
time,  is  much  greater  for  quick  than  for  slow-burning  powder.  If  the 
projectile  should  not  be  down  against  the  cartridge,  although  the  impact 
of  the  projectile  force  of  the  gases  against  the  rear  end  of  the  shot  would 
be  greater  than  the  pressure  of  the  powder,  the  shot  would  not  have  so 
high  a  velocity  communicated  to  it,  because  the  time  of  the  action  of  the 


106          EXPERIMENTS  ON  HEAVY  OKDNANCE. 

force  against  the  shot  would  be  less.  Therefore  if  a  shot  should  be 
placed  just  at  the  muzzle  of  the  gun,  the  force  of  the  impact  of  the  gases 
against  the  rear  end  of  the  shot  would  be  maximum,  and  the  velocity 
communicated  to  the  shot  would  be  a  minimum. 

10.  Q.  And,  therefore,  the  highest  velocity  is  attained  from  a  gun  by 
having  the  shot  down  against  the  cartridge,  is  it  ? 

A.  When  the  charge  is  rammed  or  forced  down  against  the  powder 
cartridge  in  such  a  manner  as  to  close  up  all  the  grains  of  powder  into 
close  contact  with  each  other,  and  with  the  surface  of  the  bore  or  chamber 
of  the  gun,  the  velocity  of  the  projectile  is  greatest,  and  the  strain  upon 
the  gun  least  possible  from  a  like  charge  in  a  like  gun. 

11.  Q.  Did  a  gun  ever  burst  from  the  premature  bursting  of  a  shell  in 
the  bore  ? 

A.  If  a  shell  should  be  burst  in  the  muzzle  of  a  15-inch  gun  containing 
a  charge  such  as  would  nearly  burst  the  gun  in  that  part,  but  not  quite, 
the  force  with  which  the  fragments  of  the  shell  would  be  projected  against 
the  surface  of  the  bore  would  cause  numerous  and  deep  indentations  in 
the  metal  of  the  gun ;  the  cause  of  such  indentations  could  not  be  easily 
misunderstood  or  overlooked,  especially  if  we  should  be  informed  or 
believed  a  loaded  shell  lying  in  that  part  of  the  bore  had  been  exploded 
while  at  rest.  The  part  of  the  shell  forming  its  largest  diameter  would 
be  projected  against  the  surface  of  the  bore  violently,  and  it  would  surely 
leave  its  mark  if  the  force  of  the  explosion  reached  nearly  to  the  force 
necessary  to  rupture  the  gun.  Yet  I  have  examined  23  large  guns  which 
have  burst  at  the  muzzle  :  three  of  them  were  Dahlgren  11-inch  guns ; 
one Dahlgren  8-inch  gun ;  two  10-inch;  six  15-inch;  two  army  42  pound- 
ers, rifled ;  one  32-pounder,  rifled ;  and  eight  large  Parrott  guns.  I  was 
informed,  either  by  the  persons  who  were  present  at  the  time  of  the 
accident,  or  by  the  ordnance  department,  that  many  of  the  accidents 
were  attributed  to  the  premature  explosion  of  the  shells  in  the  bore;  I 
therefore  examined  them  carefully,  and  found  not  a  single  case  exhibiting 
any  enlargement  of  the  bore  whatever,  and  not  the  slightest  indentation. 
It  is  quite  impossible  that  so  many  cases  of  rupture  could  have  occurred, 
or  even  that  one  could  have  happened  from  the  premature  discharge  or 
explosion  of  the  shells  in  the  bore,  without  permanent  enlargement  of  the 
bore  or  indentation,  which  would  be  apparent  to  the  practiced  eye  even 
without  the  aid  of  instruments. 

12.  Q.  If  it  is  not  the  bursting  of  the  shells  in  the  bore,  how  do  you 
account  for  the  bursting  of  the  guns  at  the  muzzle  I 

A.  There  is  a  correlation  and  conservation  of  heat  and  force.  Heat  and 
ability  to  perform  work  are  exact  equivalents.  Force,  while  being 
resolved  into  motion,  if  restrained,  is  changed  into  heat ;  if  unrestrained, 
into  work  performed.  So,  if  a  man  of  the  weight  of  150  pounds  climb  a 
ladder  to  the  interior  of  the  dome  of  the  Capitol,  100  feet  high,  his  body 
becomes  charged  during  his  ascent  with  the  ability  to  perform  a  definite 
amount  of  foot-pounds  of  work  in  descending  again  exactly  15,000.  If 
he  should  grasp  a  rope  which  passed  freely  over  a  pulley  and  was  fixed 
at  its  opposite  end  to  a  weight  of  149  pounds  down  at  the  floor,  by  the 
descent  of  his  body  the  weight  might  be  raised  to  the  same  height  from 
which  he  descended.  To  raise  such  a  weight  of  149  pounds  to  such  a 
height  14,900  foot-pounds  of  work  would  be  performed,  100  foot-pounds 
less  than  the  descending  weight  would  be  capable  of  performing.  The 
difference  of  100  foot-pounds  being  expended  in  friction  would  be 
simultaneously  resolved  into  heat.  Suppose  the  rope  were  fixed  so  as  not 
to  flow  over  the  pulley,  but  was  grasped  in  the  hands  with  such  compara- 
tive tightness  as  to  permit  slipping  slowly  downwards ;  so  much  heat 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          107 

would  be  evolved  by  the  friction  as  to  burn  the  flesh  off  the  bones  of  the 
hand.  Thus,  if  the  projectile  is  restrained  in  the  gun  by  rubbing  too 
tightly  along  the  bore,  the  friction  might  create  heat  enough  to  weld  the 
projectile  to  the  gun.  If  one-half  its  projectile  force  should  be  restrained, 
one-half  of  its  ability  to  perform  work  would  be  expended  in  heating  the 
surface  of  the  bore  almost  instantaneously ;  this  heat,  of  course,  would 
be  communicated  to  the  interior  in  advance  of  heating  the  outside  of 
the  tube ;  the  force  of  the  longitudinal  and  radial  expansion  would  be 
sufficient  to  burst  the  gun. 

13.  Q.  By  the  conservation  of  force  cannot  you  account  for  the  burst- 
ing of  guns  elsewhere  than  at  the  muzzle  ! 

A.  In  a  report  made  by  Captain  Thomas  Edson  on  (the  bursting  of) 
the  13-inch  Rodman  gun  at  Fort  Monroe  arsenal  during  the  firing  from 
it,  July  23  and  27, 1864,  three  rounds  were  fired  on  the  27th  with  55  pounds 
of  Dupont's  ]STo.  5  powder  and  a  solid  shot  of  283  pounds;  the  Eodman 
instrument  gave  a  pressure  for  the  three  rounds  of  152,000, 170,000,  and 
180,000  pounds,  respectively:  for  the  first  two  rounds  1,505  feet  initial 
velocity;  for  the  third  round  1,800  feet.  On  the  23d  two  rounds  were 
fired  with  the  same  kind  of  charge.  At  the  first  round  the  so-called 
pressure  was  200,000  pounds  to  the  square  inch ;  at  the  second  round 
160,000  pounds,  and  the  initial  velocity  was  only  1,188  feet  per  second. 
The  rate  of  the  velocity  of  these  rounds,  and  the  others,  with  the  pressures 
shown,  should  have  been  1,600  feet  per  second ;  about  one-fourth  of  the 
force  of  the  charge  was  expended  therefore  in  some  other  manner  than  in 
giving  velocity  to  the  shot.  Let  us  suppose  it  to  have  been  expended  in 
friction  along  the  bore ;  resolve  it  into  foot-pounds,  according  to  this  new 
light, "  the  conservation  of  force,"  and  see  what  the  result  is  in  plain  figures. 
The  shot  13  inches  in  diameter  has  132  square  inches  area,  against  which 
the  expansive  force  of  the  powder  acts  in  ejecting  it  from  the  gun. 
This  area  multiplied  by  the  pressure  in  pounds  to  the  square  inch, 
132x160,000  =  21,120,000  pounds  of  instant  pressure  against  the  shot. 
In  order  to  simplify  the  calculation  I  will  assume  that  this  full  pressure 
acts  against  the  shot  while  it  is  moving  along  the  bore,  a  distance  of  five 
feet.  Then  21,120,000x5  =  105,600,000  foot-pounds.  One  quarter  of 
these  foot-pounds  would  be  equal  to  raising  26,400,000  pounds  one  foot 
high,  one  pound  26,400,000  feet  high,  or  2,534,400,000  pounds  one- 
eighth  of  a  foot  high;  all  these  amounts  of  work  being  equivalents.  All 
this  intense  force  might  be  exerted  in  as  practical  a  manner  to  burst  a 
gun  by  unequal  expansion,  which  would  result  from  heating  the  surface 
of  the  bore  in  advance  of  heating  the  outside,  as  the  same  force  could  be 
directed  by  the  best  intelligence  in  any  other  manner;  therefore  it 
becomes  necessary  to  devise  guns  and  projectiles,  if  possible,  which  shall 
not  in  any  contingency  have  any  friction  between  the  projectile  and  the 
surface  of  the  bore. 

14.  Q.  Is  the  pressure  upon  the  square  inch  of  surface  for  a  small 
charge  less  upon  the  square  inch  of  surface  of  the  chamber  than  for  a 
large  charge"? 

A.  There  cannot  be  any  materially  greater  force  to  act  upon  the 
chamber  of  a  gun,  resulting  from  a  large  charge  of  powder,  than  from  a 
small  one.  A  cubic  inch  of  powder  fired  in  a  chamber  which  it  fills  will 
exert  the  same  pressure  upon  the  square  inch  of  surface  of  the  chamber 
as  would  be  exerted  upon  a  square  inch  of  surface  of  a  chamber  with  a 
cubic  foot  of  capacity  if  also  filled  with  powder. 

15.  Q.  Has  the  friction  of  the  gases  or  the  grains  of  powder  the  effect 
to  heat  the  interior  of  a  gun! 

A.  The  friction  of  unburnt  grains  of  powder  sliding  along  the  surface 


108          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

of  the  bore  would  of  course  have  a  tendency  to  heat  the  interior  of  the 
gun  more  rapidly  than  the  exterior ;  but  there  is  a  greater  force  than 
this,  which  I  discovered  in  the  following  manner — also  resulting  from 
friction:  In  firing  a  12-pounder  rifled  gun  in  1861,  I  found  that  1£ 
pound  of  powder  gave  a  higher  velocity  than  any  larger  charge  of  pow- 
der. After  proving  the  fact  by  firing  the  gun  for  range,  a  few  shots 
were  projected  into  a  sand  butt  with  three-pound  charges,  and  upon 
recovering  the  projectile  I  found  that  part  of  the  powder  charge  adhered 
to  the  rear  of  the  shot,  pressed  into  a  cake,  apparently  as  hard  as  soap- 
stone,  which  it  resembled.  Upon  this  I  concluded  that  the  loss  of  velocity 
was  due  to  the  fact  that  not  more  than  one  and  a-half  pounds  of  powder 
could  be  burned  in  a  gun  of  that  calibre,  but  did  not  notice  at  this  time 
that  the  velocity  was  much  less  with  three  pounds  than  with  a  pound 
and  a-half.  At  a  later  time  I  had  occasion  to  fire  a  breech-loading  gun 
of  12  pounds  calibre,  in  which  the  chamber  was  larger  than  the  bore, 
and  having  inserted  the  cartridge,  accidentally,  previous  to  the  insertion 
of  the  projectile,  I  endeavored  to  force  the  cartridge  through  towards 
the  muzzle,  and  finding  it  did  not  move  easily,  I  applied  increased  force, 
using  a  block  of  wood  with  the  blows  of  the  sledge  to  drive  it  through, 
but  in  vain.  I  then  endeavored  to  drive  it  back  by  the  same  means, 
but  could  not  move  it  en  masse  either  way.  Upon  digging  out  the  pow- 
der with  a  pointed  instrument  of  wood  it  was  found  in  a  hard  cake 
resembling  that  which  adhered  to  the  shot  in  the  previous  experiment 
mentioned.  From  this  I  drew  the  conclusion  that  the  retardation  of 
the  projectile  resulted  from  excessive  friction  which  attended  the  slip- 
ping of  the  unburned  powder  along  the  bore  jammed  behind  the  shot  as 
it  would  be  when  the  cartridge  of  an  excessive  charge  was  ignited  at 
the  rear  end  of  the  chamber. 

16.  Q.  How  can  this  be  prevented  ? 

A.  When  large  charges  are  used  it  may  be  almost  entirely  prevented 
by  igniting  the  cartridge  at  the  front  end  ;  so  the  projectile  only  will 
have  to  be  moved  along  the  bore  while  the  unburnt  powder  is  forced 
back-  into  the  chamber. 

17.  Q.  Do  you  know  any  other  injurious  forces  which  are  exerted  to 
burst  guns  which  may  be  so  controlled  as  not  to  have  injurious  effect  ? 

A.  I  do.  Guns  are  usually  mounted  so  as  to  recoil  backwards  in  a 
plane  different  from  the  plane  of  the  bore  when  the  gun  is  elevated. 
An  improvement  in  the  manner  of  mounting  in  this  respect  is  needed: 
I  exhibit  on  Plate  XIV  a  plan  which  I  have  designed  for  this  purpose. 
A  gun  should  recoil  backwards  while  the  shot  is  being  ejected  exactly 
in  the  opposite  direction  to  that  in  which  the  shot  is  moving;  then 
there  would  be  no  greater  pressure  upon  the  bottom  of  the  bore  from 
the  projectile  than  that  due  to  the  weight  of  the  shot  when  at  rest. 

The  effect  of  the  gun  in  recoiling  in  any  other  direction  is  to  divert 
the  shot  from  its  aim,  and  results  in  greatly  increased  friction  along  the 
bottom  of  the  bore  detracting  from  the  range  of  the  projectile  and  exert- 
ing forces  which  have  a  tendency  to  break  off  the  muzzle  of  the  gun  or 
burst  it  at  the  muzzle.  When  a  gun  is  burst  at  the  muzzle  by  any  of 
these  forces  in  combination  or  alone,  no  mark  is  left  on  the  bore  to 
indicate  the  cause  of  the  accident,  which  is  therefore,  as  I  have  saidbefore, 
erroneously  attributed  to  the  premature  bursting  of  the  shells  in  the 
bore.  If  it  happen  that  the  gun  bursts  when  a  solid  shot  is  fired  from 
it,  or  at  a  round  when  a  shell  is  fired,  which  does  not  prematurely  burst, 
the  bursting  is  attributed  all  the  same,  and  the  premature  bursting  of 
some  shell  previously  fired  is  referred  to  as  the  cause  of  the  accident. 
Thus  the  whole  subject  is  shrouded  in  impenetrable  mystery  and  another 
a  incongruous  result"  added  to  the  already  too  long  list. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          109 

18.  Q.  What  is  the  cause  of  the  enlargment  of  the  bore  of  a  gun  at 
the  seat  of  the  shot  so  frequently  referred  to  in  the  reports  of  the  ord- 
nance department. 

A.  When  the  pressure  of  the  powder  acts  upon  the  rear  of  the  pro- 
jectile in  a  gun,  and  before  its  front  has  motion  imparted  to  it,  the  rear 
has  moved  forward;  thus  the  axis  which  coincides  with  the  longest 
axis  of  the  bore  of  the  gun  is  reduced  in  length  and  the  diameter  of  the 
projectile  is  increased  in  all  radial  directions.  While  this  occurs,  the 
projectile  being  only  in  contact  with  the  bottom  of  the  bore,  it  must 
either  penetrate  the  metal  of  the  gun  at  the  place  of  contact  or  the  pro- 
jectile must  be  lifted  up  bodily.  Usually  the  result  is  a  little  of  both ;  as  the 
projectile  receives  its  forward  impetus  along  the  bore,  it  therefore  re- 
bounds; from  its  elasticity  and  the  elasticity  of  the  metal  of  the  gun,  it 
jumps  upward  and  strikes  the  top  of  the  bore  a  little  forward  of  its  first 
position ;  glancing  then  downwards,  it  rebounds  again  from  the  bottom, 
and  so  goes  on  balloting  from  top  to  bottom  until  it  escapes  from  the 
muzzle.  This  balloting  has  injurious  effects  upon  the  bore  of  the  gun; 
it  results  in  increased  friction  and  consequently  in  increased  temper- 
ature, which  retards  the  velocity  of  the  shot  and  destroys  the  paral- 
lelism of  the  bore  and  of  the  gun,  inasmuch  as  it  penetrates  it  or  injures 
it  irregularly ;  of  course  guns  are  sometimes  enlarged  by  the  direct  pres- 
sure of  the  powder  arrested  by  tension. 

19.  Q.  Cannot  this  be  prevented? 

A.  It  can  be  when  due  to  ballotting  or  upsetting  of  the  projectile  by 
supporting  the  projectile  centrally  in  the  gun  with  equidistant  windage 
all  around,  previous  to  igniting  the  charge. 

20.  Q.  Is  there  any  direct  communication  of  heat  from  the  gases  of 
the  powder  to  the  surface  of  the  bore  ? 

A.  The  heat  of  the  gases  of  powder  except  by  friction,  or  by  the  aid 
of  currents,  is  communicated  slightly  or  slowly.  The  heat  of  steam  is 
communicated  rapidly  to  any  colder  surface  with  which  it  is  in  contact ; 
because,  as  the  heat  is  expended  below  180,  a  vacuum,  or  partial  vacuum, 
is  formed.  The  current  is  thereby  forced  to  flow  with  inconceivable  rap- 
idity to  the  surface,  receiving  the  heat,  whereby  the  heat  of  the  other 
steam,  previously  at  a  distance  from  the  cooling  surface,  is  communicated. 
In  this  steam  is  quite  different  from  other  gases  containing  heat,  such  as 
air,  or  the  gases  resulting  from  the  combustion  of  the  gunpowder,  all 
of  them  being  non-conductors,  and  all  of  them  having  an  extremely  low 
specific  heat.  Only  the  gas  which  is  in  contact  with  the  surface  of  the 
bore  of  a  gun  imparts  its  temperature  to  it ;  thus  it  is  thereafter  inter- 
posed as  a  non-conductor  between  the  surface  and  the  hotter  gas  at  a 
distance ;  which  is  thus  prevented  from  giving  its  heat  to  the  surface. 
With  that  part  of  the  gas  which  is  flowing  through  the  vent  or  passing  by 
the  windage  of  the  shot  itself  it  is  different.  The  large  quantity  pre- 
sented to  the  surface  in  quick  succession  in  such  a  case  communicates 
its  heat,  and  immediately  it  passes  away,  giving  place  to  other  quantities. 
In  this  manner  a  larger  proportion  of  heat  is  communicated  to  the  vent 
than  to  another  equal  surface  to  which  the  gas  is  exposed  in  a  gun :  first, 
because  the  fire  is  lighted  at  the  vent,  and  the  hot  gas  flows  longer  over 
that  part ;  and  second,  because  the  vent  passage  is  least  liable  to  obstruc- 
tion. In  the  case  of  the  rifle  projectile  the  windage  is  usually  entirely 
obstructed,  and  in  smooth-bore  guns  unburnt  powder  grains,  or  the  cart- 
ridge bag  may  be  forced  forward  to  stop  the  windage,  and  the  passage 
of  the  heated  gas  past  the  shot.  After  the  bore  becomes  worn  at  the 
seat  of  the  shot,  and  the  vent  is  injured,  more  heat  is  communicated  than 
while  the  gun  is  new.  More  heat  would  always  be  communicated  to  the 


110  EXPERIMENTS    ON   HEAVY    ORDNANCE 

vent  and  the  bore  of  the  gun,  by  the  passage  of  the  hot  gas,  after  they 
had  become  worn  and  rough  from  the  slipping  of  the  gases  over  the 
rough  surface,  causing  increased  friction  and  as  a  tendency  to  restrain  the 
expansion  of  the  gas  in  motion,  as  well  as  the  motion  of  the  projectile, 
causes  force  to  be  changed  into  heat,  by  friction  which  may  act  injuriously 
upon  the  gun,  by  unequally  heating  it  and  straining  it  through  unequal 
expansion. 

21.  Q.  Has  no  way  been  devised  to  prevent  the  heating  of  the  gun 
metal  about  the  vent  ? 

A.  A  variety  of  the  plans  may  be  adopted  to  close  the  vent  against 
the  escape  of  the  gas ;  or  the  charge  may  be  ignited  without  any  vent, 
and  thus  a  serious  cause  of  injury  to  guns  of  large  calibre  may  be 
obviated. 

22.  Q.  Then  is  there  any  manner  which  may  be  adopted  to  prevent 
the  communication  of  heat  along  the  surface  of  the  bore? 

A.  The  unequal  expansion  which  results  from  the  direct  communication 
of  the  heat  of  the  gases  of  powder,  or  the  heat  evolved  from  friction  of 
the  gas  or  of  unburnt  grains  of  powder,  or  powder  jammed  against  the 
projectile,  or  rubbing  or  balloting  of  the  projectile  against  the  surface 
of  the  bore,  is  the  principal  cause  of  bursting  of  guns.  The  injurious 
effects  may  be  prevented  by  making  the  gun  elastic  between  the  inner 
metal  and  the  reinforce,  according  to  a  plan  which  I  have  devised,  Plates 
XIII  and  XLV,  and  present  herewith. 

23.  Q.  What  advantages  does  this  gun  possess  over  the  Parrott  gun  of 
the  same  calibre,  cast  hollow,  in  your  estimation  ? 

A.  It  can  be  made  to  have  a  finer  texture  or  molecular  construction  of 
the  metal  (see  Plate  VII)  without  injurious  tensions,  greatly  increased 
strength  to  resist  the  forces  acting  upon  it  as  a  gun,  from  the  increased 
rate  of  decarbonization  admissible  in  its  metal,  which  will  increase  its 
tenacity ;  it  will  also  increase  the  permanent  elasticity  of  the  metal,  per 
5e,  and  in  addition  to  that,  from  its  form  or  model  it  will  have  a  wide 
range  of  elasticity  to  permit  the  radial  and  longitudinal  expansion  which 
results  from  heating  the  gun  from  the  interior  in  any  or  all  of  the 
various  ways  I  have  alluded  to.  (See  Plates  XIII  and  XIV.) 
It  can  be  made  from  the  iron  of  old  guns  ;  and  it  has  been  heretofore 
deemed  impossible  to  re-cast  the  iron  of  old  guns  into  new  ones,  as  the 
strength  and  density  are  increased  thereby,  as  can  be  learned  by  refer- 
ring to  Rodman's  book,  (Appendix  D,)  which  shows  the  strongest 
metal  does  not  make  the  strongest  gun,  although  the  reason  for  that 
seeming  paradox  is  not  very  plainly  shown.  It  is  undoubtedly  because 
of  the  increased  rate  of  decarbonization  which  results  from  remelting 
cast  iron,  keeping  it  longer  in  the  melted  state,  or  in  fusion,  giving 
greater  tensile  strength  and  the  increased  density  which  accompanies 
higher  tensile  strength,  resulting  from  further  decarbonization  of  cast 
iron.  The  higher  the  density,  the  greater  the  force  with  which  the  ex- 
pansion of  the  metal  will  be  accompanied  when  heated ;  and  the  greater 
the  force  of  unequal  expansion  when  unequally  heated,  as  well  as  the 
greater  tensions  which  will  result  from  unequal  cooling,  is  an  effect  of 
remelting  or  longer  time  in  fusion.  This  gun  (Plate  XIV)  can  be  made 
cheaper  than  the  Parrott  gun  because  no  wrought  iron  is  used  in  its  con- 
struction, and  no  iron  is  wasted  by  turning  off  the  gun  along  the  chase; 
it  will  not  be  weakened  or  unequally  heated  by  the  waste  of  gas  through 
the  vent,  because  it  has  no  vent,  the  charge  being  ignited  at  the  front 
end  of  the  cartridge  by  a  revolving  pin  inserted  through  the  cascable 
within  a  copper  tube.  Many  of  these  details  are  not  shown  in  the  draw- 
ings. The  friction  of  unburned  or  jammed  powder  along  the  bore  is 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          Ill 

also  avoided  by  lighting  the  cartridge  at  the  front  end  ;  and  the  friction 
of  the  projectile  against  the  surface  of  the  bore  is  to  be  avoided  by  hav- 
ing no  contact,  except  in  the  two  rifled  grooves,  which  are  to  be  kept 
smooth  and  polished  ;  and  the  projectile  is  to  be  supported  centrally  in 
the  gun,  bearing  only  upon  two  gibs  of  brass,  to  slide  in  the  grooves  as 
freely  as  the  cross  head  on  a  steam-engine  piston-rod  slides  upon  the 
guides,  which  will  result  favorably  in  giving  increased  velocity  to  the 
shot.  The  gun  having  but  two  grooves,  (see  details,  Plate  XIII,)  neither 
of  which  cross  the  bottom  or  top  of  the  bore,  it  remains  essentially  a 
smooth-bore  gun  for  spherical  projectiles,  and  is  also  available  as  a  rifle. 
When  spherical  shot  or  shell  are  to  be  used  the  projectile  is  to  be  sup- 
ported centrally  in  the  bore  by  three  pins  of  brass  projecting  from  its 
bottom,  to  rest  on  the  bottom  of  the  bore  like  the  legs  of  a  stool,  thus 
preventing  rubbing  contact. 

24.  Q.  Why  could  not  the  round  projectile  have  the  rifle  motion  im- 
parted to  it  ? 

A.  It  could.  I  forgot  to  mention  that  instead  of  the  pins  to  support 
the  projectile  centrally  in  the  bore  it  might  be  provided  with  the  gibs 
to  slide  in  the  grooves.  No  more  windage  should  then  be  given  to  the 
shot  than  experience  taught  would  be  equal  to  the  radial  enlargement 
under  the  pressure  of  the  gases  of  powder ;  improved  accuracy  and 
range  would  result.  The  rotary  motion  given  to  the  round  projectile 
would  not  render  its  ricochet  uncertain  5  and  the  gibs  might  be  so 
adjusted  as  to  fly  off  after  the  projectile  had  left  the  gun.  Sporting  rifles 
are  extensively  used  in  the  west  with  round  bullets. 

25.  Q.  Would  not  the  unequal  heating  you  have  described,  resulting 
from  the  friction  or  direct  heat  of  the  gas,  affect  the  interior  tube  of  this 
gun  injuriously,  or  burs  tit? 

A.  Oh,  no,  sir !  because  a  tube  having  no  more  than  four  inches  of 
thickness  may  be  melted  by  heat  communicated  entirely  to  the  interior 
surface  without  bursting  it.  Field  and  siege  guns  do  not  burst,  however 
rapidly  they  are  fired,  if  the  wall  of  metal  surrounding  the  bore  is  no 
more  than  four  inches  thick ;  it  is  only  the  metal  of  the  reinforce,  which 
surrounds  that  thickness  in  larger  guns,  which  is  ruptured  by  unequal 
expansion. 

26.  Q.  Then  why  make  any  gun  of  greater  thickness? 

A.  Simply  because  if  the  calibre  is  large  it  requires  the  strength  of  a 
thicker  Avail  to  resist  the  direct  pressure  of  the  powder.  There  is  no 
trouble  attends  making  small  guns  ;  and  it  is  to  be  noticed  that  all  gun- 
makers  have  achieved  their  reputation  on  small  guns.  Sir  William. 
Armstrong  made  a  small  gun  first,  and  it  exhibited  remarkable  qualities 
of  accuracy  and  range.  His  field  guns  afterwards  were  highly  approved. 
He  only  met  serious  difficulties  when  large  calibres,  involving  more  than 
four  inches  thickness  of  wall,  were  attempted.  So  also  with  the  guns 
produced  by  Mr.  Parrott ;  first  10-pounders,  then  20-pounders,  and  30- 
pounders,  all  of  which  were  successful  guns.  One  of  the  30-pounders 
endured  4,600  rounds,  on  Morris  island  ;  and  although  the  100-pounder 
endured  the  proof  of  slow  firing,  at  the  foundry,  showing  that  the 
strength  was  sufficient  to  withstand  the  pressure  of  the  powder,  the  first 
one  fired  rapidly,  in  service,  viz.,  the  one  on  the  steamer  Naugatuck,  in 
the  attack  on  Fort  Darling,  was  burst ;  and  afterwards  all  of  that  class 
of  guns  of  large  calibre,  and  the  necessary  thick  walls,  whenever  sub- 
jected to  conditions  which  heated  them  unequally,  burst  likewise. 

27.  Q.  Then  why  will  not  the  direct  pressure  of  the  powder  burst  the 
gun  you  propose,  which  has  a  thin  tube  of  iron  about  the  bore  ? 

A.  Because  a  pressure  nearly  equal  to  the  strength  of  the  reinforce 


112          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

is  exerted  on  the  outside  of  the  tube,  by  contracting  the  band  upon  the 
edge  of  the  webs  which  surrounds  the  tube;  each  web  being  a  beam  to 
support  the  tube  forward  and  behind  the  band,  and  if  this  pressure  exerted 
by  the  band  equals  the  pressure  the  powder  would  exert  from  the  inside 
of  the  tube,  there  is  no  tendency  to  break  it  or  enlarge  it.  The  pressure 
of  the  reinforce  is  exerted  upon  this  thin  tube  as  if  springs  were  inter- 
posed between  it  and  the  band.  (See  cross- section,  Plate  XIV.)  The 
pressure  of  the  powder  is  not  sufficient  to  bend  the  springs  further, 
although  the  greater  force,  resulting  from  heating  the  interior  to  expand 
the  tube,  may  be  sufficient  to  bend  them  to  a  slightly  greater  extent  than 
they  would  be  bent  by  the  tension  of  the  reinforce.  There  is  such  a 
wide  difference  or  margin  between  the  "  instant  pressure77  of  the  force 
which  results  from  the  pressure  of  the  powder,  and  that  of  the  force 
which  results  from  expansion  of  the  metal  by  heat,  that  it  is  quite  prac- 
ticable to  interpose  these  springs  between  the  interior  and  exterior  of 
the  gun,  and  thereby  restrain  the  pressure  of  the  powder,  and  permit 
the  expansion  by  heat,  which  cannot  be  restrained.  (See  cross-section 
of  details,  Plate  XIII.  ^ 

27.  Q.  But  the  tube  will  expand  lengthwise,  also ;  how  can  you  pro- 
vide for  that? 

A.  By  the  peculiar  form  of  the  springs,  or  webs ;  they  are  made  to  have 
elasticity  for  the  lengthwise  as  well  as  the  radial  expansion.  (See  ele- 
vation, 200-pounder  rifle,  Plates  XIII  and  XIV.) 

28.  Q.  Could  this  gun  be  made  of  wrought  iron? 

A.  It  could  very  well ;  but  the  ductility  of  wrought  iron  is  a  very 
objectionable  quality  for  guns.  Wrought  iron  will  stretch  permanently 
under  a  force  which,  if  exerted  upon  equal  ultimate  strength  of  cast  iron, 
would  only  enlarge  it  within  its  permanent  elasticity,  and  it  would 
recover  after  the  force  was  removed,  and  wrought  iron  would  not. 
Wrought  iron  is  also  softer,  and  would  be  more  easily  abraded  and 
scratched  in  the  bore ;  it  is  more  rapidly  wasted  by  rusting  and  more 
subject  to  the  action  of  acids  of  powder  than  cast  iron  or  steel ;  the 
carbon  protects  the  latter  from  the  rapid  action  of  oxygen  or  acids ; 
carbon  having  a  stronger  affinity  for  oxygen  than  iron  has,  the  oxygen 
unites  with  the  carbon  first.  We  owe  it  to  this  fact  that  we  can  make 
wrought  iron  from  cast  iron,  to  do  which  only  requires  the  extraction  of 
the  carbon  from  the  cast  iron  or  steel.  Wrought  iron  has  the  other 
objectionable  quality  as  a  material  for  guns,  viz:  that  it  cannot  be  made 
homogeneous.  It  is  not  practicable  to  melt  and  flow  it  in  the  liquid 
state  into  the  required  form — of  uniform  structure — as  we  can  with  cast 
iron ;  it  must  be  welded,  and  the  welds  are  places  of  weakness.  The 
cost  of  a  wrought-iron  gun  is  about  four  times  as  great  as  the  cost  of  a 
cast-iron  gun. 

29.  Q.  I  see  in  Holley's  book  (Fig.  160)  an  account  of  fissures  which 
occurred  in  a  large  mass  of  wrought  iron,  which  were  attributed  to  some 
other  cause  than  bad  welding.  Is  it  common  to  find  defects  in  that  kind 
of  iron? 

A.  Fissures  of  that  kind  (Plate  X)  only  happen  when  the  mass  is  large, 
and  are  caused  by  "  the  contraction  from  the  centre  towards  the  circum- 
ference as  the  mass  cools."  They  are,  in  fact,  an  effect  of  unequal  con- 
traction resulting  from  unequal  cooling,  and  resemble  the  cavities  found 
in  the  centre  of  large  masses  of  cast  iron  half-way  between  the  cooling 
surfaces,  if  exposed  to  an  equal  rate  of  cooling  from  all  the  surfaces.  I 
have  here  a  piece  of  iron,  broken  from  the  centre  of  a  large  mass,  which 
you  will  notice  is  of  a  very  coarse  structure,  (Fig.  4,  Plate  VII;)  the  faces 
of  the  crystals  are  one-fourth  of  an  inch  across;  and  another  piece  cast 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          113 

at  the  same  time  from  the  same  lot  of  melted  iron  of  a  smaller  diam- 
eter. The  molecular  structure  of  the  iron  of  the  thin  part  (Fig.  1, 
Plate  VII)  is  entirely  different  5  it  is  as  fine  grained  as  cast  steel.  These 
peculiarities  of  structure  pf  iron,  (Plate  VII,)  due,  it  is  supposed,  entirely 
to  the  different  rate  of  cooling  or  freezing  from  the  liquid  to  the  solid 
state,  are  not  sufficiently  attended  to  by  metal  workers.  The  finer  the 
molecular  structure,  the  stronger  and  better  the  fabrication  made  from 
the  iron.  In  wrought  iron  the  same  differences  of  size  of  grain  can 
be  seen.  With  this  knowledge  I  designed  the  guns  shown  on  Plates 
XIII  and  XIV. 

30.  Q.  It  has  been  represented  to  us  that  fibrous  wrought  iron  is  much 
stronger  than  crystallized  iron ;  is  that  so  f 

A.  Undoubtedly  j  even  to  a  greater  degree  than  the  fine-grained  cast 
iron  excels  in  tenacity,  elasticity,  and  density  the  coarse-grained  iron. 
The  difference  of  structure  is  shown  in  Figs.  5  and  6,  Plate  XI.  In  a 
mass  as  large  as  is  required  for  a  gun  there  is  no  such  thing  as  fibre  ; 
the  structure  is  entirely  changed  by  cooling  from  or  heating  to  the  weld- 
ing temperature,  as  slowly  as  a  large  mass  must  be  heated  or  cooled ; 
the  molecular  structure  is  entirely  changed  by  once  heating  to  the  weld- 
ing temperature,  if  the  mass  is  large. 

31.  Q.  Among  the  forces  which  you  have  mentioned  as  resulting  from 
the  combustion  of  gunpowder,  you  have  referred  to  the  expansive  force ; 
is  not  that  a  principal  force  to  be  restrained,  and  can  it  be  restrained  ? 

A.  It  can ;  the  whole  of  the  expansive  force  of  gunpowder  under  com- 
bustion has  been  frequently  restrained  when  fired  in  a  chamber  which 
it  filled.  I  have  conducted  such  experiments  myself,  and  have  heard  of 
the  experiments  of  others,  in  which  the  force  was  restrained  completely. 
However,  if  I  were  about  to  design  or  make  a  gun  of  any  calibre  which 
had  been  made  previously  by  any  other  person  of  the  same  material  and 
which  had  endured  one  or  two  heavy  charges  equal  in  weight  of  and 
rapidity  of  combustion  of  the  charge  I  wished  to  use,  I  would  depend 
upon  the  data  relating  to  strength  by  thickness  of  wall  in  that  gun,  and 
adopt  equal  or  greater  area  of  cross  and  longitudinal  sections ;  then,  by 
increased  tenacity,  density,  and  elasticity  in  the  metal  used,  get  a 
margin  of  strength  to  restrain  the  direct  pressure.  I  would  then  take 
care  to  have  110  injurious  tensions  from  the  rate  of  cooling,  and  with  the 
elasticity  which  my  improved  model  would  give  to  provide  for  the  une- 
qual expansion,  I  would  expect  to  get  a  gun  which  would  absolutely 
restrain  the  direct  pressure,  and  permit  the  unequal  expansion  resulting 
from  firing,  which  need  not  be  restrained. 

32.  Q.  What  is  initial  tension,  so  frequently  referred  to,  and  how  does 
it  affect  the  endurance  of  guns  I 

A.  Initial  tension  is  an  inert  force  or  strain,  inaugurated  in  a  gun  or 
any  other  piece  of  metal,  induced  usually  by  unequal  cooling,  causing 
one  part  of  the  mass  to  endeavor  to  pull  away  from  or  towards  another 
part,  or  both.  The  part  which  cools  first  in  any  mass  is  subjected  to  a 
strain  of  compression,  and  the  part  which  cools  last  to  a  strain  of  exten- 
sion. The  castings,  Plate  XV,  which  I  have  prepared  and  exhibited  to  the 
committee,  lately  placed  in  the  hall  of  the  old  House  of  Bepresentatives, 
were  intended  to  represent  the  excess  of  this  tension  from  unequal  cool- 
ing. These  castings  were  referred  to  in  a  late  report  of  the  Chief  of 
Ordnance,  General  Dyer,  as  having  been  prepared  by  u  ignorant  or 
designing  persons,"  and  the  maker  was  credited  with  having  hindered 
the  furnishing  by  the  department  of  1,915  large  guns.  I  hope  you  will 
credit  me  with  having  prevented  the  perpetration  of  a  gigantic  swindle 
upon  the  treasury  thereby. 
Eep.  No.  266 8 


114          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Metals  expand  while  being  heated  with  a  force  which  exactly  equals 
the  measure  of  their  ability  to  resist  compression  at  each  different  tem- 
perature if  their  expansion  be  resisted  sufficiently,  and  contract  in  cool- 
ing with  a  force  which  equals  the  resistance  to  extension  of  the  same 
metal.  These  experimental  castings,  it  may  be  seen,  have  broken  in 
their  strongest  part,  where  the  area  of  cross-section  ruptured  is  twelve 
square  inches.  If  we  assume  the  tensile  strength  of  the  iron  to  be  only 
20,000  pounds  to  the  inch,  the  tension  necessary  to  break  it  amounted 
to  240,000  pounds,  the  outside  bars  having  a  larger  amount  of  cooling 
surface,  while  the  quantity  of  metal  to  be  cooled  is  less,  became  frozen 
while  the  iron  of  the  middle  bar  was  in  the  liquid  state.  The  later  con- 
traction of  the  part  cooled  last  (the  contraction  being  restrained  by  the 
rigidity  of  the  part  cooled  first)  was  the  cause  of  the  rupture.  If  the 
length  of  the  casting  had  been  less  it  might  have  happened  that  the 
extent  of  the  contraction  of  the  middle  bar  would  have  been  within  the 
"  permanent  elasticity,"  and  the  measure  of  ductility  of  the  iron ;  it 
would  not  in  that  case  have  been  broken,  although  the  tension  might 
have  been  nearly  great  enough  to  break  it ;  it  would  then  be  in  the 
state  of  initial  tension.  It  can  be  seen  that  a  casting  might  be  made 
and  strained  so  nearly  to  the  point  of  rupture,  that  the  heat  of  the  hand, 
(if  warmer  than  the  iron,)  laid  upon  the  compressed  part,  would  be  suf- 
ficient to  complete  the  rupture  or  burst  it. 

Those  Rodman  guns  which  have  burst  in  the  foundry  previous  to  hav- 
ing been  subjected  to  the  powder  proof,  were  burst  by  the  excess  of  the 
initial  tension,  caused  by  cooling  the  gun,  or  the  cast  block  from  which 
the  gun  was  to  be  made,  from  the  interior"? 

33.  Q.  Are  the  views  contained  in  your  evidence  in  relation  to  metals, 
force  of  powder,  and  endurance  of  guns,  confirmed  by  the  opinions  of 
experts,  by  the  reports,  and  by  recorded  authorities? 

A.  They  are  my  conclusions,  based  upon  a  careful  reading  of  reports 
and  authorities,  upon  my  own  practical  experience  as  a  metal  worker, 
my  own  experiments  and  observations  as  a  gun  maker,  and  a  long  and 
earnest  study  of  the  natural  philosophy  involved  in  the  subject.  If  you 
will  permit  me,  I  will  revise  my  evidence  and  interpolate  references  to 
the  reports,  authorities,  and  experiments' upon  which  my  statements  are 
founded. 

34.  Q.  You  can  do  so.    How  will  the  cost  of  testing  guns  upon  the 
plan  you  have  proposed  compare  with  the  system  now  practiced  by  the 
army  and  navy  ordnance  departments  ? 

A.  The  cost  would  be  immeasurably  less,  as  the  extreme  proof  would 
determine  at  once  the  quality  of  the  gun  and  of  all  other  guns  made  of 
the  same  calibre,  form,  or  model,  material,  and  manipulation  of  material  ; 
while  it  can  be  seen  that  the  old  extreme  proof  determined  nothing  except 
that  the  particular  gun  tried  either  burst  or  did  not  burst,  enlarged  or 
did  not  enlarge;  that  the  vent  either  did  or  did  not  wear,  and  that  the 
interior  either  cracked  or  did  not  crack.  The  uncertainties  attending 
the  proof  of  guns  are  referred  to  frequently  in  the  reports  a's  u  incon- 
gruous results,77  while  the  question  relating  to  the  endurance  of  guns 
remains  involved  in  mystery.  General  Dyer,  in  his  last  report,  dated 
October  19,  1868,  says: 

In  the  last  annual  report  from  this  office  the  unanimous  opinion  of  the  board  on  the  aruia^ 
ment  of  the  fortifications  ******  was  quoted,  showing  the  necessity  of  a  large 
number  of  smooth-bore  and  rifle  cannon  for  such  armament.  In  pursuance  of  this  opinion, 
approved  by  the  War  Department,  and  at  the  request  of  the  Chief  of  Engineers,  a  few  of 
these  cannon  have  been  ordered,  and  are  now  nearly  finished  and  ready  for  trials  to  test  their 
power  and  endurance. 

In  the  report  of  the  same  officer  for  the  preceding  year,  the  endurance 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          115 

of  a  12-inch  Eodraan  rifle  gun  was  referred  to  as  establishing  that  guns 
of  that  class  exhibited  endurance  superior  to  any  gun  of  the  calibre  in 
the  world,  without  referring  to  the  important  fact  that  four  only  of  that 
kind  of  gun  had  ever  been  made,  and  that  three  of  them  had  burst  pre- 
viously to  the  date  of  that  report.  Since  that  time  the  fourth  one  has 
burst,  and  it  is  now  rumored  that  two  or  three  others  referred  to  in  the 
report  of  October  19,  1868,  as  of  the  few  which  have  been  ordered,  have 
been  disabled  during  the  experiments  on  iron  defences  by  the  engineers. 
The  extraordinary  part  of  this  business  is  that  while  the  ordnance  depart- 
ment of  the  army  is  engaged  apparently  in  efforts  to  bolster  up  the 
character  of  guns  which  fail  so  suddenly  that  it  is  difficult  to  make  the 
report  and  print  it  before  the  guns  are  disabled,  the  Chief  of  Ordnance 
of  the  navy  says,  in  his  corresponding  annual  report: 

Opinions  differ  quite  as  widely  (referring  apparently  to  almost  every  question  involved  in 
designing,  constructing,  mounting,  and  using  ordnance)  in  regard  to  the  preferable  mode  of 
developing  ordnance  power ;  whether  it  shall  be  by  smooth  or  rifle  bores ;  by  loading  at 
breech  or  muzzle ;  made  of  iron,  cast  or  wrought,  or  from  steel;  solid,  or  in  connected  parts. 
The  relation  of  mass  to  velocity  is  also  unsettled. 

It  seems  to  me  that  it  is  plainly  the  duty  of  Admiral  Dahlgren  to 
report  his  own  conclusions  in  relation  to  these  important  points,  while  it 
seems  also  quite  as  plain  that  he  prefers  to  continue  expending  public 
money  in  repeating  old  worn-out  kinds  of  experiments,  and  recording 
the  most  minute  and  inconsequential  facts  in  relation  to  such  experi- 
'ments,  instead  of  wrenching  himself  in  the  public  service,  to  the  extent  he 
would  if  he  should  advance  an  original  idea*>r  give  an  opinion  with  a  reason. 
Who  is  there  so  ignorant  about  ordnance  in  these  days  as  not  to 
know,  for  instance,  whether  it  is  practicable  or  better  to  load  guns  of 
the  larger  calibres  at  the  breech,  after  the  exhaustive  experiments  con- 
ducted in  England  with  the  Whitworth  and  Armstrong  guns,  if  the  guns 
did  not  fail ;  and  that  the  return  to  muzzle-loaders  in  that  country  for 
large  calibres  was  on  account  of  the  failure  of  the  guns,  and  not  other- 
wise !  Who  does  not  know  the  relation  of  mass  to  velocity  ?  Mass  or 
weight  is  one  element  of  ability  in  a  projectile  to  perform  work,  and  velo- 
city the  other.  Could  not  all  the  experience  of  Admiral  Dahlgren  enable 
him  to  state  as  a  fact,  that  a  projectile,  however  heavy  or  large  it  might 
be,  could  not  penetrate  air,  water,  wood,  earth,  stone,  or  iron,  if  it  had 
no  motion  or  velocity,  and  that  it  could  not  do  so  either,  even  with 
velocity  or  motion,  if  it  had  no  mass  or  weight?  Has  Admiral  Dahlgren 
never  seen  the  calculations  of  Captain  Noble,  of  the  royal  artillery  of 
England,  of  the  foot  tons  of  work  per  inch  of  circumference,  stored  up 
in  projectiles  having  different  weights  and  velocities,  or  the  simple  rule 
upon  which  the  calculation  is  made?  If  he  has  not,  what  is  the  use  of 
continuing  expenditures  of  public  money  for  experiments  under  such 
obtuse  direction  ?  No  valuable  conclusion  can  ever  be  arrived  at  in  so 
indirect  a  manner.  On  the  22d  of  November,  1862,  this  same  officer,  in 
his  report  as  Chief  of  Ordnance,  referring  to  "  the  construction  and 
armament  of  our  ships  of  war,"  said:  "And  yet  no  definite  conclusion 
has  been  reached  in  regard  to  either  of  these  important  problems;"  and, 
although  a  war  was  then  raging,  referred  on  the  same  page  to  the  part 
of  the  question  relating  to  the  guns,  with  the  refreshing  complacency 
exhibited  in  the  following  quotation:  "so  that  we  have  the  leisure  to 
consider  and  devise  any  other  species  of  ordnance  that  may  be  better 
adapted  to  the  purpose,  and  are  not  precipitated  inlo  hasty  or  questionable 
measures."  Obtuseness  and  complacency  of  the  navy  ordnance  bureau 
is,  however,  no  more  effectually  opposed  to  progress  in  the  art  of  pro- 
ducing guns,  than  the  politic  shrewdness  or  smartness  of  the  army 


116          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

ordnance  corps,  and  their  selfishness  in  precluding  from  the  sacred 
precincts  of  the  inner  sanctuary  of  the  department  all  inventors  of  guns. 

35.  Q.  After  a  gun  has  burst  could  you  determine  whether  it  was 
•pressure  of  the  powder,  toa  great  tension,  or  too  little,  or  the  unequal 
heating  from  the  interior  which  was  the  principal  cause  of  the  rupture 
from  the  nature  of  or  direction  of  the  fracture  ? 

A.  I  think  we  can  determine  that  almost  with  certainty.  It  is  to  be 
noticed  that  all  unbanded  guns  burst  with  such  uniform  direction  of 
fracture  as  to  lead  to  the  conclusion  that  the  bursting  is  according  to 
law ;  at  the  same  time  this  direction  is  not  that  one  which  could  possibly 
result  from  pressure  of  the  powder  alone.  About  twenty  years  since  Gen- 
eral Rodman  proceeded  to  consider  the  forces  acting  to  burst  a  gun,  and 
assumed  the  gun  to  be  made  up  of  staves  shown  by  diagrams  in  his  re- 
ports, (see  Plate  Y,  Fig.  1  and  Fig.  3,)  and  assumed  correctly  enough  that 
the  effect  of  this  pressure  would  be  to  bend  these  imaginary  staves  out- 
ward, as  shown  in  Fig.  1,  Plate  Y.  He  then  erected  a  diagram  to  show 
the  kind  of  fracture  which  would  result  from  pressure;  in  this  he  was  also 
singularly  correct.  This  kind  of  fracture  is  shown  by  Fig.  1,  Plate  Y. 
Its  correctness  is  shown  by  the  fracture  of  a  cylinder  actually  burst  by 
water  pressure  during  one  of  his  experiments,  (see  Fig.  7,  Plate  Y.)  Now 
I  believe  myself  to  be  the  only  person  who  ever  asked  attention  to  the 
fact  that  this  kind  of  fracture  is  a  kind  that  never  occurred  to  a  gun 
burst  by  firing.  I  was  surprised  to  find  that  General  Rodman,  however, 
had  not  yet  seen  the  point  which  I  have  urged  in  this  connection  for  the 
past  six  years,  for  in  giving  his  testimony  before  this  committee  a  few 
days  since,  he  referred  to  the  staves  and  the  strength  of  the  breech  as 
If  no  other  force  but  the  pressure  of  the  gas  measured  by  his  instrument 
had  anything  to  do  with  the  bursting  of  guns  behind  the  bottom  of  the 
bore,  where  the  pressure  don't  act  at  all.  and  expressed  the  opinion  that 
the  gun  shown  in  Fig.  2,  Plate  II,  began  to  rupture  at  the  breech  and 
split  forward,  and  he  treated  the  subject  very  tenderly  when  describing 
the  bursting  of  guns  on  improved  models,  Plates  II  and  III,  which  broke 
through  the  breech  in  the  same  manner,  although  they  have  a  greater 
thickness  at  that  part.  Plates  II  and  III  exhibit  the  general  direction  of 
fracture  in  all  unbanded  guns;  and  Fig.  4,  Fig.  5,  and  Fig.  6,  Plate  Y, 
are  intended  to  show  why  guns  burst  through  the  breech  and  refuse 
to  follow  the  direction  of  fracture  due  to  pressure  alone,  according  to  the 
diagram,  Fig.  2,  Plate  Y,  Fig.  4,  same  plate,  shows  the  curved  form 
which  the  two  outside  plates  of  three  iron  ones  would  assume  if  heat 
should  be  communicated  to  their  inside  surfaces  only  by  heating  the 
middle  plate  red  hot  and  adjusting  it  between  the  other  two,  when  cold 
and  straight.  By  imagining  three  such  plates  placed  upon  the  diagram  of 
a  burst  gun,  as  in  Fig.  6,  Plate  Y,  the  cause  of  the  invariable  bursting 
through  the  breech  in  guns  of  this  kind  can  be  understood.  The  heat 
added  to  the  interior  of  the  gun  causes  the  extension  lengthwise  of  the 
interior  iron,  and  forces  the  reinforce  into  the  curved  form  shown  in  Fig. 
4,  Plate  IY.  This  is  also  illustrated  in  Fig.  1,  Plate  Y.  The  reinforce 
extended  by  the  expansion  of  the  interior  and  the  refusal  of  the  exterior 
to  extend  with  it  is  the  principal  cause  of  the  rupture  undoubtedly. 

The  Parrott  banded  gun,  Fig.  1,  Plate  I,  has  the  same  character  of 
fracture  from  the  same  cause.  If  a  narrow  band  had  been  placed  on 
the  columbiad,  Fig.  1,  Plate  YI,  just  over  the  seat  of  the  shot,  although 
it  might  have  prevented  the  rupture  under  the  band,  it  would  have  had 
no  tendency  to  have  prevented  that  part  of  the  rupture  reaching  from 
forward  of  the  trunnions  back  to  the  band;  and  this  explains  that  kind  of 
rupture  shown  in  the  Parrott  gun,  Fig.  4,  Plate  I,  Fig  5,  Plate  I, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          117 

which,  however,  only  cracked  on  the  outside.  Ruptures  along  the  chase 
and  at  the  muzzle  have  been  sufficiently  explained  in  answer  to  previous 
questions.  It  is  important  to  consider  the  cause  of  the  blowing  out  of 
the  breech.  Plate  X,  Fig.  1,  shows  a  Whitworth  gun,  which  was 
one  of  two  disabled  in  the  naval  battery  on  Morris  island;  the  inner  tube 
extended  and  protruded  one  inch,  as  shown.  This  inner  tube  would 
not  have  extended  so  far  out  at  the  breech  if  it  had  been  allowed  to  ex- 
pand when  heated  by  firing  in  all  other  directions.  The  bands  prevented 
it  from  expanding  radially.  If  the  band  had  been  shrunk  on  with  screw 
threads  fitting  upon  the  inner  tube  so  as  to  prevent  extension  lengthwise 
as  well  as  radially,  the  gun  would  have  burst  with  the  same  direction  of 
fracture  as  is  shown  in  columbiad,  Fig.  2,  Plate  V,  or  else  it  would  have 
broken  transversley  in  the  same  manner  the  300-pounder  Armstrong,  Figs. 
3  and  4,  Plate  X,  broke,  i.  e.s  transversely;  so  also  the  heating  the  Parrott, 
Fig.  2,  Plate  X,  only  half  way  through  the  wall  of  cast  iron  under  the  band 
had  the  tendency  to  expand  the  interior  radially  and  longitudinally,  but 
its  expansion  (rememember  only  heated  half  the  thickness  of  the  cast  iron 
from  the  inside)  was  restrained  radially  by  the  band.  The  result  was,  the 
breech  was  pushed  out  just  the  same  as  the  300-pounder  Armstrong, 
Fig.  4,  Plate  X.  Thus  it  can  be  seen  that  unequal  expansion  of  the 
metal  of  the  gun  from  the  interior,  resulting  from  the  direct  heat  of 
the  gas  of  the  powder  undergoing  combustion,  or  the  heat  coming  from 
friction,  is  the  principal  cause  of  all  the  different  kinds  of  ruptures  of 
guns. 


APPENDIX  B. 

Correspondence. 

WASHINGTON,  D.  0.,  December  24, 1868. 

SIB  :  I  have  the  honor  to  request  that  you  will  furnish  as  soon  as  prac- 
ticable answers  to  the  following  questions,  for  the  information  of  the 
Joint  Select  Committee  on  Ordnance: 

1.  What  different  calibres  and  kinds  of  guns  larger  than  32-pounder 
smooth-bores  and  30-pounder  rifles  are  now  mounted  on  or  prepared  for 
the  fortifications? 

2.  What  is  the  nature  of  the  proof  or  experiments  to  which  the  different 
kinds  and  calibres  before  mentioned  have  been  subjected  to  respectively 
to  enable  the  department  to  determine  upon  the  propriety  of  accepting 
the  guns  for  service? 

3.  How  many  rifled  guns  of  8-inch  calibre  or  larger,  cast  hollow,  have 
been  made  either  for  the  army  or  the  navy,  and  subjected  to  proof  or  ex- 
periment!   What  has  been  the  endurance  of  each  of  the  guns?    What 
is  the  present  state  of  each,  and  what  was  the  nature  or  extent  of  the 
proof  on  experiments  in  each  case  I 

4.  What  guns  cast  hollow  for  the  army  have  exhibited  cracks  or  rup- 
tures on  the  outside  previous  to  being  subjected  to  the  powder  proof, 
together  with  the  nature  and  extent  of  the  rupture? 

Very  respectfully,  your  obedient  servant, 

J.  M.  HOWARD, 
Chairman  Joint  Select  Committee  on  Ordnance. 

Lieutenant  Colonel  T.  J.  TREADWELL, 

Acting  Chief  of  Ordnance,  Washington,  D.  C. 


118  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

ORDNANCE  OFFICE,  WAR  DEPARTMENT, 

Washington,  January  23,  1869. 

SIR:  I  have  the  honor  to  report  as  follows  in  reply  to  your  communi- 
cation of  the  24th  ultimo : 

Question  1.  What  different  calibres  and  kinds  of  guns,  larger  than 
32-pounder  smooth-bores  and  30-pounder  rifles  are  now  mounted  on  or 
prepared  for  the  fortifications  ? 

There  are  mounted  or  ready  to  be  mounted  at  the  forts  as  follows: 

SMOOTH-BORES. 

1  20-inch  Eodman  gun. 
294  15-inch  Eodman  guns. 

1  13-inch  Eodman  gun. 
1, 233  10-inch  Eodman  guns. 

147  10-inch  columbiads. 
155  8-inch  Eodman  guns. 
339  8-inch  columbiads. 
30  8-inch  sea-coast  howitzers. 

33  8-inch  siege  howitzers. 
143  42-pounder  guns. 

2  16-inch  mortars. 

17  13-inch  mortars,  sea-coast. 
2  12-inch  mortars,  sea-coast. 

34  10-inch  mortars,  sea-coast. 
59  10-inch  mortars,  siege. 

26  8-inch  mortars,  siege. 

2, 516 — total  smooth-bores. 


RIFLED  GUNS. 


2  12-inch  Eodman  guns. 
28  300-pounder  Parrott  guns. 
48  200-pounder  Parrott  guns. 
133  100-pounder  Parrott  guns. 
34  4J-inch  siege  guns. 

245 — total  rifled  guns. 


Besides  the  foregoing  there  are  at  the  arsenals,  available  for  mounting — 

SMOOTH-BORES. 

2  15-inch  Eodman  guns. 
24  10-inch  Eodman  guns. 

8  10-inch  columbiads. 
46  8-inch  Eodman  guns. 
63  8-inch  columbiads. 
15  9-inch  Dahlgren  guns. 

2  10-inch  sea-coast  howitzers. 

6  8-inch  navy  guns. 
58  8-inch  sea-coast  howitzers. 
184  8-inch  siege  howitzers. 


EXPERIMENTS    ON    HEAVY    ORDNANCE.  119 


31  42-pounder  guns. 
1  16-inch  mortar. 

41  13-inch  mortars,  sea-coast. 

70  10-inch  mortars,  sea-coast. 

30  8-inch  mortars,  sea-coast. 
124  10-inch  mortars,  siege. 
154  8-inch  mortars,  siege. 

859 — total  smooth-bores. 


RIFLED  GUNS. 


1  8-inch  Eodman  gun. 

11  300-pounder  Parrott  guns. 
33  200-pounder  Parrott  guns. 
55  100-pounder  Parrott  guns. 

12  7-inch  wrought-iron  guns. 
73  42-pounders,  banded. 

75  4J-inch  guns. 
107  32-pounders,  banded. 

367— total  rifled  guns. 


RECAPITULATION. 


Smooth-bores.  Rifled. 

At  forts 2, 516  245 

At  arsenals 859  367 

Total 3, 375  612 


Question  2.  What  is  the  nature  of  the  proof  or  experiments  to  which 
the  different  kinds  and  calibres  before  mentioned  have  been  subjected 
respectively  to  enable  the  department  to  determine  upon  the  propriety 
of  accepting  the  guns  for  service  f 

Prior  to  1861  the  proof  of  iron  guns  was  three  rounds — two  with  a 
charge  of  powder  equal  to  one-half  of  the  weight  of  the  shot,  two  shot 
and  one  wad ;  the  third  a  charge  of  powder  one-third  the  weight  of  the 
shot,  one  shot  and  one  wad. 

For  columbiads  the  proof  was  two  rounds — 10-inch,  first  round,  20 
pounds  of  powder,  one  shot,  and  one  wad;  second  round,  24  pounds  of 
powder,  one  shot,  and  one  wad. 

For  the  8-inch — first  round,  12  pounds  of  powder,  one  shot,  and  one 
wad ;  and  for  the  second  round,  15  pounds  of  poAvder  and  one  shell. 

The  proof  of  howitzers  and  mortars  was  a  corresponding  scale. 

In  1861  the  proof  for  all  guns  was  fixed  as  follows :  (Ordnance  Manual, 
1861,  page  30:) 

15-inch  columbiad,  3  rounds,  50  pounds  powder,  and  1  shell. 
10-inch  columbiad,  3  rounds,  18  pounds  powder,  and  1  shot. 
8-inch  columbiad,  3  rounds,  12  pounds  powder,  and  1  shot. 
32-pounder  gun,  3  rounds,  9  pounds  powder,  and  1  shot. 
24-poundor  gun,  3  rounds,  8  pounds  powder,  and  1  shot. 
18-pounder  gun,  3  rounds,  6  pounds  powder,  and  1  shot. 
12-pounder  gun,  3  rounds,  4  pounds  powder,  and  1  shot. 


120          EXPEKIMENTS  ON  HEAVY  OKDNANCE. 

8-inch  siege  howitzer,  3  rounds,  4  pounds  powder,  and  1  shot. 

24-pounder  howitzer,  iron,  3  rounds,  3  pounds  powder,  and  1  shot,  strapped. 

Field  guns,  bronze,  3  rounds,  $  weight  of  shot,  and  1  shot,  strapped. 

32-pounder  howitzer,  bronze,  3  rounds,  3£  pounds  powder,  and  1  shot,  strapped. 

24-pounder  howitzer,  bronze,  3  rounds,  2-£  pounds  powder,  and  1  shot,  strapped. 

12-pounder  howitzer,  bronze,  3  rounds,  1£  pounds  powder,  and  1  shot,  strapped. 

12-pounder  mountain  howitzer,  bronze,  3  rounds,  •£  pound  powder,  and  1  shot,  strapped. 

Coehorn  mortar,  3  rounds,  £  pound  powder,  and  1  shell. 

13-inch  sea-coast  mortar,  3  rounds,  20  pounds  powder,  and  1  shell. 

10-inch  sea-coast  mortar,  3  rounds,  10  pounds  powder,  and  1  shell. 

10-inch  light  mortar,  3  rounds,  5  pounds  powder,  and  1  shell. 

8-inch  light  mortar,  3  rounds,  2£  pounds  powder,  and  1  shell. 

4^-inch  rifled  siege  guns,  3  rounds,  4£  pounds  powder,  and  1  shot. 

3-inch  rifled  siege  guns,  3  rounds,  1^  pounds  powder,  and  1  shot. 

In  January,  1862,  when  it  was  determined  that  guns  should  be  cast 
hollow  and  cooled  from  the  interior,  the  following  requirements  were 
prescribed :  That  one  trial  gun  should  be  made  by  each  founder  receiv- 
ing orders  ~or  accepting  a  contract;  the  gun  should  be  made  of  warm 
or  cold  blast  charcoal  iron,  to  have  a  tenacity  of  not  less  than  30,000 
pounds  per  square  inch,  to  be  determined  by  specimens  taken  from  the 
sinking  head  of  the  gun  and  from  a  cylinder  cast  from  the  same  heat 
and  from  the  same  metal ;  the  trial  guns  to  be  fired  1,000  rounds  with 
service  charges  of  powder,  200  with  solid  shot  and  800  with  shells,  and 
if  the  gun  stood  the  test  the  order  to  be  filled  with  guns  made  of  the 
same  metal  treated  in  the  same  manner,  and  to  be  received  upon  endur- 
ing the  proof  established  in  1861. 

The  7-inch  wrought-iron  rifles  were  proved  by  firing  10  rounds  with 
20  pounds  of  powder  and  one  shot  weighing  125  pounds. 

The  rifled  guns  heretofore  procured  having  been  considered  entirely 
as  experimental,  a  provisional  proof  was  fixed  for  such  guns. 

The  Parrott  rifle  guns  were  procured  as  a  necessity  during  the  war, 
but  before  putting  them  in  service  one  100-pounder  was  subjected  to  a 
test  of  1,000  rounds  with  charges  of  10  pounds  of  powder  and  one  shell, 
which  it  endured ;  subsequently  the  200-pounders  and  300-pounders  were 
subjected,  one  of  each  to  a  test  of  100  rounds — the  200-pounder  with 
charges  of  powder  of  15  and  16  pounds,  and  one  shell  of  150  pounds,  and 
the  300-pounder  with  charges  of  25  pounds  of  powder  and  one  shell 
weighing  252  pounds,  which  test  they  endured. 

All  guns  of  these  three  calibres  subsequently  procured  were  proved 
with  10  rounds  of  similar  charges. 

In  the  fall  of  1864  the  department  appointed  an  officer  to  superintend 
the  construction  of  cannon,  with  authority  to  dictate  to  founders  the  kinds 
of  metal  they  shall  use,  the  manner  in  which  it  shall  be  treated,  and  the 
properties  it  shall  possess  after  being  cast  into  guns,  such  as  tenacity, 
specific  gravity,  initial  strain,  and  texture  of  fracture.  These  being  satis- 
factory, the  responsibility  of  the  powder-proof  was  assumed  by  the  depart- 
ment. All  guns  cast  hollow  and  cooled  from  the  interior,  since  that 
period,  have  been  received  on  these  conditions,  but  are,  nevertheless, 
subjected  to  proof  according  to  the  regulations  of  1861. 

The  ordnance  board,  at  its  meeting  of  January,  1868,  fixed  the  proof 
of  15  and  13-inch  guns  at  two  rounds  of  100  pounds  of  powder  and  one 
solid  shot  for  the  former,  and  the  same  number  of  rounds  of  80  pounds 
of  powder  and  one  solid  shot  for  the  latter,  and  further  recommended 
that  all  15-inch  guns  heretofore  procured,  whether  proved  or  not,  should 
be  proved  with  this  charge  of  100  pounds  of  powder  and  one  shot.  This 
will  be  done  as  fast  as  the  guns  are  mounted,  or  other  suitable  facilities 
afforded  for  the  purpose. 

Question  3.  How  many  rifled  guns  of  8-inch  calibre,  or  larger,  cast 


EXPERIMEMTS  ON  HEAVY  ORDNANCE.          121 

hollow,  have  been  made  either  for  the  army  or  the  navy  and  subjected 
to  proof  or  experiment  I  What  has  been  the  endurance  of  each  of  the 
guns  ?  What  is  the  present  state  of  each,  and  what  was  the  nature  or 
extent  of  the  proof  or  experiments  in  each  case  ? 

The  number  of  rifled  cannon  of  8-inch  calibre  and  larger,  cast  hollow, 
which  have  been  procured  by  this  department,  is  as  follows : 

Three  12-inch  Eodman  guns;  three  8-inch  Rodman  guns;  forty-one 
200-pounder  Parrott  guns ;  forty  300-pounder  Parrott  guns. 

The  first  8-inch  rifle,  which  was  made  at  Fort  Pitt  foundry,  was  sub- 
mitted to  a  test  of  1,047  rounds  with  charges  ranging  from  9  to  16  pounds 
of  powder  and  one  projectile,  and  burst  at  the  last  round. 

Two  8-inch  rifles  were  subsequently  made  at  the  South  Boston  foundry, 
and  were  tested,  one  with  flanged  and  the  other  with  expanding  projec- 
tiles, and  with  charges  of  powder  ranging  from  14  to  16  pounds. 

The  one  fired  with  flanged  projectiles  burst  at  the  80th  round ;  the  one 
fired  with  expanding  projectiles  has  endured  808  rounds  and  is  still  ser- 
viceable. 

The  first  12-inch  Eodman  rifle  was  fired  472  times,  with  charges 
ranging  from  35  to  70  pounds  of  powder,  principally  50  pounds,  and  one 
projectile,  and  burst  at  the  last  round. 

A  12-inch  gun,  cast  hollow  and  rifled  on  the  Atwater  principle,  was 
turned  over  to  the  ordnance  department  by  the  navy,  and  was  tested  at 
Fort  Monroe.  The  history  of  this  gun,  prior  to  its  transfer,  is  not  known. 
It  was  fired  at  Fort  Monroe,  30  rounds  with  from  50  to  55  pounds  of 
powder  and  one  expanding  shot  or  shell,  and  burst  at  the  last  round. 

Two  12-inch  Eodman  rifles  were  recently  procured  and  have  been  fired, 
one  at  Fort  Monroe  and  the  other  at  Fort  Delaware. 

Detailed  reports  of  the  firing  made  with  rifled  guns  have  heretofore 
been  furnished  to  the  committee,  except  the  firing  of  8-inch  South  Boston 
rifle,  No.  2,  subsequent  to  the  771st  fire,  the  12-inch  No.  1  from  the  428th 
to  the  472d  fire,  and  the  firing  with  the  last  two  12-inch  rifles ;  and  copies 
of  these  reports  are  appended  hereto. 

Copies  of  the  preliminary  experiments  made  with  the  Parrott  200- 
pounders  and  300-pounders  have  also  been  heretofore  furnished  to  the 
committee,  and  are  respectfully  referred  to.  Two  of  these  300-pounders 
and  eleven  200-pounders  have  failed  in  service;  but  it  cannot  be  stated 
what  portions  of  these  were  cast  hollow  or  solid. 

Question  4.  What  guns  cast  hollow  for  the  army  have  exhibited  cracks 
or  ruptures  on  the  outside  previous  to  being  subjected  to  the  powder 
proof,  together  with,  the  nature  and  extent  of  the  rupture  I 

No  gun  cast  hollow  for  the  army  which  exhibited  cracks  or  ruptures 
on  the  outside  previous  to  being  subjected  to  powder  proof  has  been 
offered  by  the  founder,  or  received  by  the  United  States.  Several  such 
guns,  to  the  number  of  98,  exhibiting  defects,  were  made  for  the  army, 
but  were  either  withdrawn  by  the  founders  or  rejected  by  the  inspectors. 

The  nature  and  extent  of  the  defects,  as  described  in  the  manufac- 
turers' reports,  are  as  follows : 

15-inch  guns 6 

10-inch  guns 82 

8-inch  guns 1 

300-pounder  Parrott 1 

8-inch  siege  mortars 8 

Of  the  first,  two  were  for  dra wholes,  one  for  being  too  large  in  bore, 

one  for  too  low  tenacity,  one  cracked  in  lathe,  and  one  condemned  in  pit. 

Of  the  second,  sixteen  were  for  drawholes,  twelve  for  holes  in  bore, 


122          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

thirty-one  for  low  tenacity,  one  for  high  density,  one  for  metal  too  soft, 
seven  failed  in  casting,  and  nine  failed  in  mechanical  tests,  one  for  too 
much  initial  strain,  one  condemned  in  mill,  two  cracked,  and  one  burst 
in  lathe. 

The  300-pounder  condemned  in  mill. 

The  8-inch  gun  for  holes  in  muzzle,  and  the  8-inch  siege  mortars  con- 
demned by  the  founder. 

Very  respectfully,  your  obedient  servant, 

T.  J.  TBEADWELL, 

Bvt.  Lieut.  Col.  and  Major  of  Ordnance,  in  charge. 
Hon.  J.  M.  HOWARD, 

Chairman  Joint  Select  Committee  on  Ordnance,  U.  S.  Senate. 


WASHINGTON,  D.  0.,  December  24,  1868. 

SIR  :  I  have  the  honor  to  request  that  you  will  furnish,  for  the  infor- 
mation of  the  Joint  Select  Committee  on  Ordnance,  answers  to  the 
following  questions: 

1.  What  is  the  total  number,  kinds,  calibres,  and  weights,  respectively, 
of  guns  now  or  at  any  time  mounted  on  iron-clad  ships  of  the  United 
States,  from  the  time  of  the  arming  of  the  first  monitor  to  the  present 
time? 

2.  How  many  trial  guns  were  originally  or  at  any  time  procured  or 
fired  to  extreme  proof  as  the  basis  of  the  acceptance  of  the  different  kinds 
and  calibres  of  guns  mounted  on  such  iron-clad  ships  ? 

3.  What  was  the  character  of  the  extreme  proof,  ^ordinary  proof,  and 
experiments,  to  which  each  system,  kind,  and  calibre,  was  severally  sub- 
jected'? 

4.  How  far  has  the  navy  Ordnance  Bureau  accepted  the  tests,  proofs, 
and  experiments  made  by  the  army  ordnance  department  towards 
enabling  the  bureau  to  determine  what  kind  of  guns  should  be  adopted 
for  service,  and  how  far,  within  the  knowledge  of  the  bureau,  has  the 
army  ordnance  department  accepted  the  tests,  proofs,  and  experiments 
of  the  navy  as  conclusive  towards  enabling  it  to  determine  the  proper 
system  to  be  adopted  in  arming  the  fortifications  with  heavy  guns? 

5.  What  fissures,  cracks,  and  ruptures,  (together  with  the  locality  and 
extent  of  the  same,)  have  at  any  time  been  noticed  or  reported  to  the 
bureau  as  having  occurred  on  the  outside  of  guns  larger  than  32-pounders, 
previous  to  the  guns  having  been  subjected  to  the  powder  proof;  also, 
what  cracks,  fissures,  and  ruptures  have  been  noticed  or  reported  on  the 
inside  of  guns  previous  to  firing;  together  with  the  kind  of  gun,  and 
whether  the  notice  or  report  was  official  or  otherwise? 

6.  What  fissures  or  cracks  have  been  reported  to  the  bureau  as  having 
occurred  upon  the  outside  or  inside  of  guns  larger  than  32  pounders, 
during  proof  or  experiments  with  powder,  together  with  the  nature  or 
extent  of  the  accident,  where  the  gun  was  not  completely  burst? 

7.  What  was  the  nature  of  the  extreme  proof  and  the  ordinary  proof 
prescribed  for  guns  of  large  calibre  by  the  bureau  in  the  years  1850, 
1855,  1860,  and  1865,  and  also  at  the  present  time;  also,  so  far  as  is 
known  to  the  bureau,  what  was  the  extreme  proof  and  ordinary  proof 
for  like  guns  prescribed  by  the  army  ordnance  department  at  the  same 
dates? 

8.  On  what  occasion  was  the  15-inch  gun  subjected  by  the  navy  to 
the  most  rapid  firing  for  as  many  as  fifteen  consecutive  rounds,  with  shot 
or  shell,  and  with  nearly  uniform  intervals  of  time  between  the  shots ; 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          123 

what  interval  of  time  elapsed  between  the  respective  rounds,  and  fur- 
ther, whether  the  gun  was  fired  in  service  or  during  experiments ;  also, 
what  official  knowledge,  if  any,  is  possessed  by  the  bureau  of  15-inch 
guns  having  been  fired  by  the  army  in  a  similar  manner  in  service  or 
during  experiments  ? 

9.  Give  like  information  with  regard  to  the  8  and  10-inch  Parrott  rifles. 

10.  What  has  been  the  most  rapid  firing  for  any  number  of  consecu- 
tive rounds  with  the  15-inch  gun,  the  larger  Parrott  rifles,  or  the  hollow 
cast  rifles,  with  nearly  uniform  intervals  between  the  shots? 

11.  What  15-inch  guns  or  rifles  of  large  calibre  were  injured,  disabled, 
or  burst  while  in  service  during  the  late  war,  or  while  undergoing  proof 
or  experiment,  together  with  the  nature  of  the  gun  and  the  character  of 
the  injury? 

12.  What  system  of  rifled  guns  of  150  pounds  calibre  or  larger  have 
been  subjected  to  proof  or  experiment  by  the  navy?    What  guns  of  that 
calibre,  or  larger,  have  been  adopted  or  accepted  for  experiment  by  the 
navy? 

13.  To  what  proof  on  experiments  has  each  system  and  calibre  which 
has-been  accepted  been  subjected?    Which  system  exhibited  the  greatest 
endurance?    Which  the  least?    What  has  been  the  average  endurance  of 
each  system  and  calibre  for  all  the  guns  made,  tested  and  experimented 
with  ?    What  system  of  rifled  guns  of  large  calibre  is  now  approved  by 
the  Ordnance  Bureau  of  the  navy  ? 

The  committee  respectfully  request  that  answers  to  these  questions  be 
given  as  early  as  practicable. 

Very  respectfully,  your  obedient  servant, 

J.  M.  HOWAED, 

Chairman  Joint  Select  Committee  on  Ordnance. 
Bear- Admiral  JOHN  A.  DAHLGREN, 

Chief  of  Ordnance,  Navy  Department,  Washington,  J).  C. 


BUREAU  OF  ORDNANCE,  NAVY  DEPARTMENT, 

Washington  City,  February  11,  1869. 

SIR  :  I  have  the  honor  to  transmit  herewith  replies  to  the  questions  of 
your  honorable  committee,  which,  I  regret  to  say,  are  more  or  less  incom- 
plete. 

I  have  done,  however,  as  much  as  the  time  has  permitted  since  receiv- 
ing the  wishes  of  the  committee  on  the  25th  of  December  last. 
I  am,  sir,  with  great  respect,  your  obedient  servant, 

J.  A.  DAHLGEE^, 
Rear-Admiral  and  Chief  of  Bureau. 
Hon.  JAMES  M.  HOWARD, 

Chairman  Joint  Select  Committee  on  Ordnance,  U.  S.  Senate. 


Reply  to  query  1. 

There  have  been  three  calibres  of  cannon  mounted  on  sea-going  iron- 
clads of  the  navy,  viz : 

Pounds. 

11-inch,  of  my  design,  smooth  bore 16,000 

Short  15-inch,  of  my  design,  smooth  bore 42,000 

Long  15-inch,  not  of  my  design 42,800 

Eifled  8-inch  (150-pouuder)  Parrott 16,500 


124          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

The  first  monitor  carried  two  15-inch  guns. 

The  vessels  of  the  class  next  built  were  larger,  and  most  of  them 
carried  in  the  turret  one  15-inch  (short)  gun  and  one  11-inch,  such  as 
the  Passaic,  Moiitauk,  Katskill,  Weehawken,  Nantucket,  Nahant,  and 
Sangamon. 

Two  of  them  carried  a  15-inch  (short  gun)  and  a  Parrott  8-inch  rifle, 
viz :  Patapsco  and  Lehigh. 

The  Mont-auk's  short  15-inch  was  replaced  by  a  long  15-inch,  and  that 
subsequently  by  another  long  15-inch. 

The  next  class  of  monitors  carried  in  the  turrets  two  short  15-inch 
guns,  viz:  Tecuinseh,  Manhattan,  Canonicus,  Saugus,  Camanche. 

Some  had  two  long  15-inch,  such  as  the  Maiiayuiik,  Tippecanoe, 
Catawba,  and  Oneota,  which  were  built  in  the  western  inland  waters, 
but  were  capable  of  ocean  service. 

The  double- turret  monitors  had  four  15-inch,  viz :  the  Monadnock, 
Miantonoinah,  Tonawanda,  Agaruenticus. 

The  large  ocean  monitor  Dictator  carried  two  15-inch  in  the  turret. 

The  Roanoke,  with  three  turrets,  had  a  15-inch  and  an  11-inch  in  one 
turret,  a  15-inch  and  150-pouuder  in  the  second  turret,  and  an  11-inch 
and  150-pounder  in  the  third  turret. 

The  river  monitors  of  one  and  two  turrets  had  only  11-inch  in  each 
turret,  viz:  Marietta,  Saudusky,  Osage,  Ozark,  Neosho,  Unipqua,  Win- 
nebago,  Milwaukee,  Chickasaw,  and  Kickapoo. 

The  Keokuk — fixed  turrets — had  one  11-inch  in  each. 

The  Onondaga  had  two  short  15-inch  and  two  150-pounder  Parrotts. 

The  New  Ironsides  had  a  covered  battery  of  14  11-inch  and  two  150- 
pounder  Parrotts. 

The  Dunderberg  was  pierced  for  16  guns,  but  never  carried  more  than 
two  15-inch  (long)  and  four  11-inch  in  battery. 

CHANGES   IN   THE  BATTERY. 

The  query  includes  guns  that  have  been  carried,  as  well  as  those  which 
are  now  carried.  I  have  to  state  that  two  of  the  Monadnock's  15-inch — 
Nos.  24  and  27 — (both  short)  were  surveyed,  condemned,  and  sold, 
(December,  1865,)  and  replaced  by  two  long  15-inch — Nos.  82  and  86. 

One  15-inch  in  the  Miantonomah  has  been  ascertained,  after  her  return 
to  the  United  States,  to  be  bored  four  inches  too  deep,  and  is,  therefore, 
condemnable,  and  must  be  replaced. 

The  Saugus's  short  15-inch  (No.  29)  was  split,  and  replaced  by  another, 
(No.  57— long.) 

The  Patapsco's  rifled  150-pounder  Parrott,  No  6,  was  cracked  in  action 
and  replaced  by  No.  40.  The  second  gun,  No.  40,  was  also  cracked,  and 
replaced  by  a  third,  No.  35,  which  was  on  board  when  the  vessel  was 
sunk  by  a  torpedo  at  the  entrance  of  Charleston  harbor. 

The  Lehigh's  15-inch,  (short,)  No.  13,  was  cracked  and  sold,  being 
replaced  by  No.  16,  (short.) 

The  Passaic's  11-inch  was  replaced  in  1863,  at  New  York,  by  an  8-inch 
rifle — no  defect  in  the  11-inch. 

The  Montauk's  short  15-inch,  No.  4,  and  11-inch,  were  replaced  by  15- 
inch,  Nos.  56,  and  80,  (both  long  guns.)  It  does  not  appear  that  these 
guns  were  displaced  on  account  of  defects,  but  only  to  make  way  for  two 
long  15-inch. 

The  length  of  the  first  15-inch,  designed  by  myself,  was  much  reduced 
in  order  to  accommodate  it  to  Mr.  Ericsson's  method  of  firing  with  the 
muzzle  inside  the  turret  5  which  was  intended  to  avoid  cutting  the  large 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  125 

apertures  in  the  turret  that  would  be  necessary  for  the  muzzle  of  the 
15-inch,  if  they  passed  through  the  wall  of  the  turret  so  as  to  be  outside 
when  fired.  The  firing  inside  made  it  necessary  to  box  the  muzzle  so  as 
to  exclude  the  smoke,  and  it  was  found  that  these  boxes  were  liable  to 
be  disabled  frequently  in  action  by  the  excessive  shock  of  the  discharge. 
15-inch  guns  were,  therefore,  cast  of  greater  length,  so  as  to  pass  out- 
side the  turret,  and  were  reduced  at  the  muzzle  so  as  to  have  the  aper- 
ture as  small  as  possible.  In  doing  so  the  gun  was  made  too  thin  at 
the  extremity  of  the  chase. 

I  drafted  the  original  navy  15-inch  gun;  the  responsibility  of  the 
modified  draft  has  been  assigned  to  the  Chief  of  the  Bureau  of  Ordnance. 
(See  memorandum — Report  of  Committee  on  Ordnance,  p.  131.) 

The  total  number  of  guns  now  or  at  "any  time  mounted  in  iron-clad 
ships  of  this  navy,"  as  given  in  the  preceding  statement,  may  be  summed 
thus:  Short  15-inch,  27;  long  15-inch,  33;  11-inch,  98;  150-pounders,  16. 

Reply  to  query  2. 

THE  15-INCH  GUN. — The  circumstances  under  which  this  class  of  gun 
was  brought  into  our  naval  service  were  so  urgent  and  abnormal  as  to 
impose  on  the  bureau  the  necessity  of  some  deviation  from  the  formula 
usually  prescribed  in  respect  to  a  trial  gun  as  a  basis  of  reception  from 
the  founders. 

The  extraordinary  efforts  of  the  rebel  government  had  enabled  it  to 
precipitate  an  iron-clad  ram  upon  our  blockading  force  in  Hampton 
Roads  in  March,  1862,  which,  being  composed  of  wooden  vessels,  suf- 
fered severe  loss  from  the  attack,  and  would  have  been  entirely  destroyed 
the  next  day  if  the  Ericsson  monitor  had  not  providentially  arrived  in 
season  to  frustrate  the  further  progress  of  the  ram.  The  moment  was 
critical,  for  just  then  our  army  was  on  the  eve  of /moving  upon  Rich- 
mond, and  the  transports  assembled  in  the  Chesapeake  for  that  purpose 
were  endangered. 

The  Navy  Department  satisfied,  as  it  might  well  be,  with  the  signal 
success  of  the  monitor,  immediately  took  measures  to  build  a  number  of 
like  model,  but  larger,  so  as  to  carry  heavier  ordnance ;  the  choice  of 
which  the  Navy  Department  itself  assumed,  and  directed  the  Bureau  of 
Ordnance  to  have  cannon  of  15-inch  calibre  made  for  the  purpose. 

The  bureau  and  myself  represented  to  the  department  that  there  were 
strong  reasons  against  this  selection  at  the  time,  viz :  A  15-inch  gun  must 
weigh  between  40,000  and  50,000  pounds.  Only  one  of  the  kind  had 
been  made,  and  its  endurance  tested,  but  with  inferior  charges.  Our  most 
experienced  founders  were  therefore  not  practiced  in  the  fabrication  of 
such  heavy  cannon,  nor,  indeed;  of  cannon  larger  than  the  11-inch,  about 
one-third  as  heavy  as  the  15-inch.  The  accidental  rupture  of  a  15-inch 
on  board  a  monitor  when  in  action  would  disable  and  might  be  fatal  to 
the  vessel. 

There  was  no  time  for  deliberate  experiment,  the  exigency  of  the  coun- 
try demanding  immediate  decision.  A  gun  of  smaller  calibre,  say  13-inch, 
would  be  more  reliable,  and  its  shot  of  280  pounds,  driven  with  greater 
charges,  would  exercise  destructive  eifect  on  any  plates  which  the  rebels 
could  oppose  to  our  fire.  In  addition  to  which  the  lesser  dimensions  of 
the  13-inch  would  admit  of  its  being  fired  outside  of  the  turret.  * 

*  I  can  say  now,  after  repeated  experience  in  battle  with  these  guns,  and  the  various  results 
derived  from  them,  in  other  ways,  that  myjopinions,  already  stated  as  submitted  to  the  Navy 
Department,  have  undergone  no  change  ;  the  complications  inseparable  from  firing  inside  or 
outside  would  alone  have  constituted  sufficient  objection  to  the  J 5-inch  if  they  had  been  as 
well  understood  as  they  are  now  ;  and  I  believe  that  the  question  of  a  suitable  cannon  for 
monitors  is  still  open  for  decision  at  some  future  day. 


126 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


The  department  adhered  to  its  selection,  and  it  became  the  duty  of  the 
bureau  to  carry  its  directions  into  execution  j  the  responsibility  of  drafting 
the  gun  was  devolved  on  ine. 

The  engagement  between  the  monitor  and  the  rebel  ram  took  place  on 
the  9th  of  March,  1862.  On  the  17th  the  department  ordered  the  bureau 
to  provide  20  15-inch  guns  and  10  20-inch,  for  the  monitors  to  be 
built.  On  the  20th  the  bureau  telegraphed  an  order  to  the  Fort  Pitt 
foundry  for  the  casting  of  15-inch  guns,  and  on  the  6th  of  April  I  had 
completed  the  draft  of  the  navy  15-inch  gun. 

There  was  only  one  foundry  in  the  country  prepared  to  enter  immedi- 
ately upon  the  fabrication  of  cannon  of  such  weight.  The  bureau  had, 
therefore,  no  choice  of  terms,  first  in  order  and  importance  of  which  was 
the  trial  of  a  gun  to  extreme  proof ;  but  the  founders  were  not  willing  to 
submit  to  other  proof  than  that  ordinarily  required  by  the  army  ordnance 
for  each  gun,  viz :  the  firing  of  three  rounds  with  50  pounds  and  a  shell, 
and  intimated  that  they  would  suspend  the  fabrication  until  these  views 
were  assented  to. 

An  appeal  was  made  by  the  bureau  to  other  foundries,  with  the  follow- 
ing result : 


Date. 

July  11,1862. 
Aug.  20, 18«  . 

Aug.  20, 186-2. 
Aug.  20,  1^62. 


Aug.  20,  18'"  2 
Aug.  20,18  2 
Aug.  20,  isr.2. 


Names. 


Foundry. 


R.  P.  Parrott |  West  Point . 

Z.  Chafee j  Providence  - . 

Juo.  Sparrow Portland  Co. 

Mathews  &  Moore . . . .  j  Philadelphia 

' 

Hinkley  &  Williams.. j  Boston...' 

Seyfert  &  McManus..|  Reading 

A    er  ^  Co .  .  Boston  . . 


Reply. 


July  18, 1862.  Declined  for  the 
present. 

August  28,1852.  Will  accept 
conditionally.  * 

August  26,  1862.     Declined. 

August  30,  1862.  Indefinite  ;  de- 
pends upon  how  many  are 
wanted. 

August    23,  1862.     Not  prepared. 

August  21,  1862.     Accepted. 

September  19,1862.  Insufficient 
facilities,  &c. 


The  Reading  foundry  alone  accepted;  but  as  no  immediate  deliveries 
could  be  expected  from  it  for  the  use  of  the  monitors,  (none  did  take 
place  until  April,  1865,)  the  bureau  had  no  alternative  but  to  submit  to 
the  terms  of  the  Pittsbtirg  foundry,  and  these,  as  already  stated,  there- 
fore constituted  the  "  basis  of  acceptance"  for  the  15 -inch  guns  then 
under  contract,  which  the  bureau  was  obliged  under  the  circumstances 
to  consent  to. 

But  to  guard  the  public  interests  against  the  calamity  of  accident  in 
a  monitor,  the  first  15-inch  gun  was  ordered  to  be  fired  50  more  rounds 
at  the  proving  ground,  and  then  sent  to  Washington  for  extreme  test. 

With  all  the  despatch  that  the  founders  could  use  the  first  naval  15-inch 
was  not  ready  when  the  first  monitor  (Passaic)  had  been  launched  and 
required  her  armament,  (30th  September.) 

When  the  second  15-inch  had  been  completed  and  mounted  in  the 
Passaic  (October  20,)  the  proof  of  the  first  gun  had  advanced  to  220 
fires. 

It  now  became  evident  that  two  15-inch  guns  could  not  be  supplied  to 
any  of  the  monitors  then  being  finished,  and  hence  an  11-inch  was  asso- 
ciated with  a  '15-inch  in  each  turret. 

With  this  armament  the  first  squadron  of  monitors  went  through  the 
active  service  of  the  co-operative  campaign  against  the  defences  of 
Charleston,  in  1863. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          127 

When  all  the  circumstances  are  considered  under  which  the  naval 
bureau  of  ordnance  accomplished  this  task,  the  extreme  and  immediate 
necessities  of  the  Union  cause  for  iron-clads,  the  unprecedented  size  of 
the  15-inch  guns,  the  absence  of  all  the  customary  data  and  experiments 
whereby  the  bureau  could  guide  its  action,  the  fatal  injury  to  the  Union 
cause  if  even  a  single  gun  of  those  placed  in  the  monitors  should  give 
way  in  any  battle—  I  say  when  all  these  are  considered,  it  will  be  con- 
ceded that  no  ordnance  authority  had  ever  been  submitted  to  a  like  respon- 
sibility, nor  received  less  credit  for  the  judicious  and  successful  manner 
in  which  it  acquitted  itself  of  that  duty  to  the  country  in  those  years  of 
sore  need,  1861,  1862. 

THE   15-INCH   G-UN. 

The  basis  of  acceptance  for  this  gun  for  use  in  turrets  was  its  estab- 
lished character  in  the  service,  and  the  tests  to  which  it  had  been  submit- 
ted to  that  end,  viz:  One  trial  gun  burst  in  July,  1855,  and  another 
April  18,  1856. 

RIFLE   150-POUNDER. 
I 

This  gun  was  brought  into  the  navy  under  circumstances  as  exigent 
and  extraordinary  as  the  15-inch,  with  even  less  substantial  data  to  pro- 
ceed on. 

So  far  as  such  heavy  rifled  calibres  were  concerned,  the  bureau  had 
scarcely  a  well-assured  fact  for  its  guidance  at  a  time  when  the  towering 
strides  of  the  rebellion  were  tasking  the  utmost  efforts  of  the  Union  gov- 
ernment, and  demands  beset  it  on  all  hands  for  these  very  cannon. 

Just  before  1  took  charge  of  the  naval  bureau  of  ordnance,  in  July, 
1862,  my  predecessor  apprised  the  Navy  Department  (July  10, 1862)  that — 

The  investigations  on  the  subject  for  rifled  cannon  had  hardly  commenced  at  the  breaking 
out  of  the  rebellion. 

The  imperative  call  for  rifled  guns  from  all  the  officers  commanding  vessels  in  the  block- 
ading squadrons,  and  the  rapid  increase  of  the  navy,  obliged  the  bureau,  as  the  department  is 
well  aware,  to  make  use  of  every  reliable  expedient  to  meet  the  demand.  It  has  not  been 
possible,  under  the  circumstances,  to  conduct  experiments  with  the  view  to  improvement  in 
the  deliberate  manner  which  has  characterized  every  important  change  in  our  naval  ordnance. 

It  may  be  proper  to  state,  in  this  connection,  that  the  ordnance  author- 
ities of  other  countries  were  then  in  no  better  plight  than  ourselves  in 
this  respect. 

The  Parrott  100-pounder  may  be  said  to  date  from  the  28th  of  October, 
1861,  as  it  was  then  brought  to  the  consideration  of  the  Bureau  of  Ord- 
nance, as  the  tiles  show  that  the  first  gun  of  that  class  had  been  taken 
to  Sandy  Hook  for  trial,  and  that  another  would  be  deliverable  in  a 
week. 

In  March,  1862,  the  first  8-inch  rifle  (which  is  the  piece  used  in  tur- 
rets) was  in  condition  for  experimental  test  when  it  was  fired  50  times. 

Under  the  necessity  of  a  pressure  more  inexorable  than  any  Ordnance 
Bureau  had  ever  before  to  sustain,  Captain  Harwood,  then  chief  of  bureau, 
ordered  two  guns  of  this  class  for  service,  (April  12,  1862.) 

There  was  no  time  to  await  the  course  of  deliberate  and  full  experi- 
ment, and  the  bureau  was  compelled  to  commit  the  rifled  8-inch  to  the 
tests  of  service  with  such  desultory  and  imperfect  trials  as  the  exigency 
permitted,  and  these  must  be  considered  to  constitute  the  only  basin  of 
acceptance  for  the  8-inch  rifle  that  was  possible. 


128 


EXPERIMENTS    ON    HEAVY    ORDNANCE. 


Reply  to  query  3. 

The  extreme  proof  to  which  the  test  naval  15-inch  gun  was  put  may 
be  given  as  follows,  viz  : 


Mammoth  powder 


Cannon  powder. 


80  rounds  of  30-pound  shell  of  330  pounds. 
20  rounds  of  35-pound  shell  of  330  pounds . 
70  rounds  of  40-pound  shell  of  330  pounds. 
22  rounds  of  45-pound  shell  of  330  pounds. 
1  round  of  50-pound  cored  shot  of  400  pounds 
49  rounds  of  50-pound  shell  of  330  pounds. 

242 


20  rounds  of  30-pound  shell  of  330  pounds. 

377  rounds  of  35-pound  shell  of  330  pounds. 

4  rounds  of  35-pound  cored  shot  400  pounds. 

20  rounds  of  40 -pound  shell  of  330  pounds. 

1  round  of  49-pound  cored  shot  400  pounds. 

27  rounds  of  45-pound  shell  of  330  pounds. 

1    round  of  45-pound  shot  of  427  pounds. 

101  rounds  of  50-pound  shell  ot  339  pounds. 

1  round  of  50-pound  canister  of  208  pounds. 

20  rounds  of  55-pound  shell  of  330  pounds. 

21  rounds  of  60-pound  shell  of  330  pounds. 
2(5  rounds  of  60-pound  cored  shot  400  pounds. 

3  rounds  of  60-pound  solid  shot  430  pounds. 

2  rounds  of  65-pound  cored  shot  400  pounds. 
2  rounds  of  70-pound  cored  shot  400  pounds. 


626 
242 


Total 868 

I 


. — The  above  is  the  report  rendered  January,  1869,  upon  a  call 
from  the  bureau  to  correct  discrepancies  in  former  reports. 

It  is  to  be  observed  that  the  mammoth  powder  is  inferior  in  strength 
to  the  cannon  powder  used  by  the  navy  in  all  heavy  guns. 

The  exact  relation  of  strength  cannot  be  given  now  for  want  of  pre- 
cise data. 

I  directed  some  practice  for  range  in  order  to  obtain  an  approxima- 
tion for  the  information  of  the  committee  $  it  resulted  that  the  mammoth 
powder  gave  only  960  (average)  yards  from  a  9-inch  gun  at  an  elevation 
of  3°  27',  whereas  the  range  with  the  standard  powder  gave  1,325  yards. 
Besides  this  greatly  decreased  power,  the  ranges  were  very  irregular ; 
extreme  difference  209  yards,  showing  irregularity  of  action  in  the  pow- 
der. It  is  to  be  remarked,  however,  that  the  powder  had  undergone . 
some  handling,  and  perhaps  exposure.  Other  powder,  of  undoubted 
quality,  will  be  obtained  and  tried. 

The  practice  for  range  was  resorted  to,  as  the  ballistic  pendulum  hap- 
pened at  the  time  to  be  temporarily  out  of  adjustment. 

The  ordinary  proof  of  the  first  34  15-inch  cannon,  to  make  them 
receivable  from  the  founder,  was  the  army-proof  required  by  Mr.  Knap, 
viz :  three  charges  of  50  pounds  of  powder  (mammoth)  and  one  shell  of 
315  pounds.  In  addition,  before  mounting  in  service,  the  bureau  ordered 
25  rounds  of  service  charges,  viz:  30  pounds  powder  (ordinary)  and  one 
shell  of  330  pounds  to  be  fired. 

The  ordinary  proof  fixed  for  the  last  66  15-inch  guns  was  three  fires 
with  35  pounds  and  shell ;  three  with  45  pounds  and  shell ;  and  three 
with  55  pounds  and  cored  shot  of  400  pounds. 


EXPERIMENTS    ON    HEAVY    ORDNANCE.  129 


THE   11-INCH   GUN. 

The  first  11-inch  gun  was  fired  1,959  times,  when  it  burst,  viz 
506  times  with  shell  of  132  pounds. 
655  times  with  shot  of  170  pounds. 
798  times  with  shell  of  132  pounds. 

1,959 


The  charge  was  in  all  cases  the  service  charge  of  15  pounds,  except  in 
nine  instances  with  10  pounds,  and  seven  times  with  5  pounds. 

This  gun  manifested  an  extraordinary  quality  of  metal ;  it  began  to 
exhibit  cracks  about  the  chamber  early  in  the  proof;  these  extended 
gradually  from  the  chamber  into  the  bore,  and  at  the  1,958th  fire  the 
crack  extended  from  the  inside  to  the  outside,  showing  a  length  of  24 
inches  on  the  outer  surface,  from  the  vicinity  of  the  vent  forward  along 
the  cylinder ;  but  the  gun  remained  whole,  and  I  deferred  the  last  charge 
until  Mr.  Alger,  who  cast  the  gun,  could  witness  this  singular  instance 
of  tenacity.  The  gun  was  then  loaded  again  and  burst  into  three  pieces; 
the  line  of  fracture  separating  the  body  of  the  gun  lengthwise,  and  the 
chase  breaking  off  outside  the  trunnions. 

THE   8-INCH  150-POUNDER. 

The  proof  gun  of  this  class  was  fired  420  times,  when  it  burst,  viz : 

Sehenkl,  (shot,) 50  rounds,  194 J  pounds, ") 

Parrott,   (shot,) 21  rounds,  172£  pounds,  !  charges,  15  pounds  navy 

Schenkl,  (shot,) 263  rounds,  194J  pounds,  [  powder. 

Hotchkiss,  (shot,) .  86  rounds,  199 J  pounds,  J 

420 


It  is  due  to  Mr.  Parrott  to  say  that  he  complained  of  the  use  of  other 
shot  in  his  gun  than  those  for  which  he  designed  it,  and  that  he  had 
protested  against  the  use  of  any  other,  (November  14,  1862  ;)  also  that 
his  term  for  the  gun  was  "  8-inch  rifle,77  and  that  in  speaking  of  it  as  a 
200-pounder,  he  only  conformed  to  the  nomenclature  of  the  ordnance 
department.  (See  article  390,  page  102.) 

On  the  other  hand,  the  bureau  considered  that  the  use  of  different 
shot  might  be  compulsory  or  desirable ;  and  it  was  therefore  its  policy 
to  know  the  capacity  of  the  gun  to  endure  such  as  were  in  common  use. 

However,  taking  into  consideration  the  points  presented  by  Mr.  Par- 
rott, it  was  plain  that  the  gun  would  have  endured  longer  with  150 -pound 
shot  than  with  shot  of  200-pounds ;  it  might  be  also  that  the  Parrott 
shot  would  strain  the  gun  less  than  other  shot. 

The  endurance,  therefore,  of  the  8-inch  rifle  was  to  be  accepted  at  a 
higher  rate  than  420  fires,  and  conformably  to  the  preference  of  Mr.  Par- 
rott the  weight  of  shot  was  fixed  at  150  pounds,  and  the  gun  was  (by 
general  order)  named  an  8-inch  150-pounder  rifle. 

The  ordinary  proof  of  each  8-inch  rifle  of  this  class  has  been  10  rounds 
with  16  pounds  of  powder  and  a  shell  of  139  pounds. 

Reply  to  query  4. 

I  am  not  aware  that  any  calibre  used  by  the  navy  has  been  adopted 
from  the  tests,  proofs,  or  experiments  of  the  army  ordnance  by  the  naval 
Rep.  No.  266 9 


130          EXPERIMENTS  ON  HEAVY  OEDNANCE. 

» 

bureau  of  ordnance,  excepting  that  of  the  15-inch,  and  then  in  that  case 
the  responsibility,  model,  and  design  of  the  gun  were  placed  upon  myself 
and  were  made  to  conform  to  those  of  the  9-inch  and  11-inch  guns  of  the 
navy,  except  in  length,  which  was  reduced  so  as  to  suit  the  limited  space 
of  the  monitor  turrets  where  they  were  to  be  placed. 

The  only  essential  particular  in  which  the  army  experience  was  con- 
sulted was  the  mode  of  casting  the  15-inch  5  and  it  is  easy  to  see  that 
under  the  circumstances  this  was  unavoidable.  15-inch  guns  had  been 
ordered  by  the  Navy  Department  for  the  monitors  then  building  ;  the 
foundry  where  the  first  15-inch  had  been  cast-,  being  the  only  one  capable 
of  such  work  at  the  time,  had  received  the  order  to  cast  the  navy  15  inch, 
and  the  proprietors  of  the  foundry  were  also  proprietors  in  part  of  the 
patent  for  hollow  casting;  there  was  no  time  to  ascertain  by  trial  what 
treatment  of  iron  was  proper  for  such  unusual  masses  of  metal  if  cast 
solid,  and  the  only  gun  of  the  kind  that  had  been  made  was  cast  hollow. 
I  believed  that  the  public  interests  required  me  to  use  the  same  means 
that  had  been  adopted  for  the  trial  15-inch  gun  for  the  army  even  at  the 
cost  of  some  strain  on  my  own  convictions.  I  did  not  hesitate,  there- 
fore, at  the  seeming  sacrifice  of  these  convictions,  with  the  express  res- 
ervation, however,  that  the  hollow  casting  should  be  used  no  longer  than 
the  occurrence  of  the  opportunity  to  investigate  the  other  method  fully 
by  experiment. 

On  the  other  hand,  in  reply  to  the  second  branch  of  the  question,  the 
army  ordnance  is  infinitely  more  indebted  to  the  navy  for  the  principle 
of  the  present  model,  on  which  its  heavy  cannon  are  now  constructed. 
This  is  contested  I  know;  it  is  denied  by  General  Rodman  that  the 
models  of  the  army  cannon  are  similar  to  those  of  mine,  and  in  this  he 
is  supported  by  other  officers  of  the  army,  as  the  committee  may  observe 
from  the  opinions  already  in  testimony  before  them.  (See  report  of 
heavy  ordnance,  February  13,  1365;  testimony  of  Generals  Ramsey, 
page  9,  and  Barry,  page  51 ;  Captain  Mordecai,  page  56;  and  Mr.  Knap, 
page  85.) 

But  there  are  other  officers  of  the  army  who  do  not  agree  that  the 
models  are  different,  viz:  Captain  Benet  of  the  army  ordnance  says, 
page  37: 

The  outline  of  both  guns  is  pretty  much  the  same. 

Colonel  Benton  of  the  army  ordnance  says,  page  69 : 

I  do  not  think  there  is  any  essential  difference,  however,  in  the  two  forms. 

(Another  part  of  his  testimony  is  not  entirely  consistent  with  this.) 
Besides,  Mr.  Parrott  says,  page  144: 

I  believe  Captain  Dahlgren  thinks  the  army  have  taken  the  models  of  his  guns,  as  the 
columbiads  are  made  essentially  as  the  Dahlgrens  were. 

I  am  not  alone,  therefore,  in  my  opinion  as  expressed  above,  and  am 
convinced  that  the  plainest  judgment  will  recognize  the  entire  similarity 
of  model  by  placing  draughts  of  the  army  guns  alongside  of  mine ;  and  if 
to  these  be  added  the  draughts  of  the  old  models — those  which  the  hollow 
casting  failed  to  make  reliable — I  think  the  judgment  will  be  assisted  by 
the  comparison. 

No  other  instance  of  importance  occurs  to  me  just  now  where  either 
bureau  has  been  indebted  to  the  other  in  the  way  referred  to  by  the 
query  of  the  committee  ;  nor  would  such  be  likely  to  arise  often,  in  view 
of  the  very  different  applications  of  ordnance  which  are  made  by  the 
army  and  navy,  and  the  great  dissimilarity  of  conditions  to  which  each 
is  subject. 

The  requirements  of  sea  and  land  service  differ  too  widely  to  admit  of 
there  being  much  in  common  in  the  choice  of  artillery  and  its  appliances. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          131 

The  business  of  both  bureaus  makes  cannon  their  specialty;  but 
while  light  artillery  is  an  essential  constituent  of  a  military  organization, 
it  is  a  mere  incident  to  naval  operations,  employed  only  in  boats  or 
where  small  bodies  of  seamen  are  landed,  and  has  no  part  whatever  in 
the  legitimate  purposes  of  a  navy — that  is,  ship  against  ship. 

On  the  other  hand  the  heavy  cannon  is  the  true — almost  the  exclu- 
sive— weapon  of  a  ship  of  war  employed  in  her  proper  business,  singly 
or  in  fleets,  while  the  campaign  of  a  long  war  may  be  carried  on  with- 
out firing  a  shot  of  heavy  calibre. 

During  the  war  of  the  rebellion  I  am  not  aware  that  the  army  ever 
fired  a  shot  in  action  from  a  15-inch  gun ;  and  even  10-inch  guns  and  8-inch 
rifles  were  sparingly  used,  while  the  heavy  cannon  of  the  navy  resounded 
along  the  Mississippi  and  the  Atlantic  shores  from  the  batteries  of  Far- 
ragut  and  Porter,  Foote  and  Dupont,  and  were  echoed  back  from  the 
British  channel  by  the  11-inch  guns  of  the  Kearsarge. 

I  have  no  idea  of  saying  that  the  army  have  no  use  for  heavy  cannon, 
but  that  as  a  general  rule  such  use  will  not  be  frequent. 

Again,  the  conditions  under  which  heavy  cannon  are  to  be  used  ashore 
or  afloat,  very  widely  and  essentially  influence  their  weight,  dimensions, 
and  appliances. 

The  gun  which  is  to  be  used  in  a  fort  may  be  as  heavy  and  as  long  as 
may  be  deemed  best  for  its  efficacy.  Not  so  in  a  ship ;  the  weight  of 
cannon  is  regulated  by  the  capacity  of  the  vessel  to  carry,  or  of  its 
decks  to  bear ;  and  the  length  by  the  space  that  is  available ;  (particu- 
larly was  this  experienced  in  the  15-inch  guns  for  the  monitors.)  Some- 
times these  conditions  may  conflict ;  there  may  not  be  space  for  all  the 
guns  a  ship  can  carry,  nor  capacity  to  carry  where  there  is  abundant 
space.  Then  there  is  the  problem  of  armament  in  pivot  or  in  broadside. 
Who  can  decide  such  questions,  or  discuss  them,  but  men  experienced  as 
seamen  and  as  ordnance  officers?  It  could  hardly  be  the  province  of  a 
soldier. 

Quite  as  much  special  nautical  aptitude  is  needed  to  determine  the 
carriages  for  sea  artillery.  Ashore  the  handling  and  pointing  of  a  heavy 
gun  where  the  platform  is  fixed  and  space  abundant,  is  comparatively  a 
small  matter  to  the  accomplishment  of  a  like  purpose  on  shipboard,  where 
every  kind  of  motion  is  to  be  provided  against. 

A  great  difference  of  construction  at  the  breech  also  occurs  between 
heavy  cannon  for  forts  and  for  ships,  occasioned  by  the  use  of  breech- 
ings  for  the  guns  of  the  latter,  which  are  never  used  in  the  cannon 
mounted  on  fortifications. 

And  who,  if  not  a  sea  officer,  shall  decide  on  the  kind  of  gun  carriage 
to  be  used  in  boats,  or  for  landing  from  boats,  and  subsequently  ashore? 

On  the  other  hand,  how  shall  a  naval  officer  possess  himself  of  the 
information  and  experience  to  fit  and  equip  the  peculiar  appliances  of 
field  artillery,  the  carriages,  caissons,  horses,  harness,  all  the  multifari- 
ous details  of  that  splendid  arm  ? 

It  would  not  be  possible  to  unite  in  any  corps  of  men  from  the  army  or 
from  the  navy  the  knowledge  and  experience  necessary  to  conduct  the 
ordnance  business  of  both,  from  the  design  and  fabrication  of  cannon 
and  its  accessories  through  all  the  details  for  service. 

The  results  obtained  in  England  and  France  from  a  consolidated 
organization  offer  us  nothing  that  should  tempt  us  to  an  imitation  of 
their  example. 

The  British  organization,  unable  to  keep  pace  with  the  feverish  appre- 
hension of  the  public,  was  subjected  to  an  entire  change.  The  direction 
was  taken  from  the  regular  authorities  and  handed  over  almost  in  fee 


132          EXPEEIMENTS  ON  HEAVY  ORDNANCE. 

simple  to  the  autocratic  control  of  a  scientific  civilian,  one  of  the  most 
accomplished  engineers  in  England ;  he  was  rewarded  in  advance  with 
knighthood  and  a  princely  gift.  What  was  the  result?  After  several 
years  of  untrammelled  effort  and  the  expenditure  of  $15,000,000,  (in  gold,) 
all  the  heavy  Armstrongs  were  altered  or  dismissed  from  service,  ashore 
and  afloat,  the  inventor's  plans  exploded  and  himself  unseated.  Eng- 
land cannot  to  this  day  feel  sure  that  she  is  in  possession  of  a  heavy 
rifled  cannon  that  is  to  be  relied  on. 

France  is  believed  to  be  no  happier  in  the  results  of  her  ordnance 
department — and  I  think  I  have  seen  in  service  the  most  recent  of  them. 

Reply  to  query  5. 

I  am  at  a  loss  to  reply  to  this  query  as  the  committee  may  intend  that 
I  should.  To  do  so  completely,  in  the  broadest  sense,  would  require  the 
examination  of  a  large  quantity  of  reports  and  correspondence  accumu- 
lated from  the  commencement  of  the  rebellion,  which  will  include  by  far 
the  greatest  number  of  9-inch  and  11- inch  cannon  now  in  the  navy,  all 
of  the  15-inch  cannon,  all  of  the  rifle  cannon  of  heavy  calibre,  and  all 
wrought-iron  guns  submitted  to  inspection  or  received.  This  has  been 
commenced,  but  at  this  date  I  have  accomplished  but  a  small  part  of  the 
task. 

With  the  permission  of  the  committee,  I  will  therefore  reply  in  a  briefer 
manner,  which  may  perhaps  meet  the  purposes  of  the  committee.  As 
regards  cast-iron  guns,  the  least  crack,  external  or  internal,  would  cause 
immediate  rejection  at  sight ;  therefore  no  founder  would  knowingly  ever 
offer  such  a  gun  for  inspection.  Cavities  occurring  in  the  bore  or  cham- 
bers of  cannon  will  cause  their  rejection  on  sight,  and  on  the  outside 
also  if  they  exceed  certain  dimensions.  As  a  sample  of  the  exact  adher- 
ence to  terms  required  of  founders  who  have  contracted  to  make  cast- 
iron  cannon  for  the  navy,  and  of  their  ready  compliance  therewith,  I  give 
the  following  extract  from  the  record,  viz : 

11-inch,  Reading  foundry,  November  10,  1862. — Not  proved.  After  bor- 
ing and  while  turning  an  indentation  or  defect  discovered  having  the 
appearance  of  a  slight  scratch.  On  probing  it,  the  unsound  part  extended 
to  the  depth  of  T3^  inch  less  than  the  prescribed  dimensions.  Caused  by 
the  inferior  quality  of  the  sand,  having  a  tendency  to  swell  under  the 
heat.  Gun  rejected.  Location  of  defect,  upper  part  of  chase  forward  of 
lock  lugs. 

Two  guns,  11-inch,  Reading  foundry,  November  16,  1862. — Not  proved; 
same  defect  from  same  cause  as  above.  Guns  thrown  aside  by  contractors. 

It  is  due  to  the  contractors  to  say  that  they  have  rarely  complained 
of  the  exact  nature  of  the  inspection  and  the  losses  to  which  it  subjected 
them.  No  appeal  from  their  bargain  has  ever  been  made  or  thought  of 
by  them. 

Besides  cracks  of  this  kind,  the  hollow-cast  guns  seem  to  be  liable  to 
others  peculiar  to  themselves,  though  I  am  not  able  to  say  whether  these 
casualties  are  of  frequent  occurrence.  The  record  notes  the  following: 

15-inch,  No.  404,  Reading  foundry,  army  gun. — Burst  open  nearly  the 
entire  length  of  the  gun,  while  in  the  heading  lathe,  with  a  loud  explo- 
sion equal  to  the  report  of  a  6-pounder. 

15-inch,  No.  419,  Reading  foundry,  army  gun. — Burst  in  the  pit  after 
removal  of  core  barrel,  and  while  cooling  the  bore  with  water  conducted 
through  it  at  the  rate  of  18  gallons  per  minute. 

15-inch,  (no  number,.*  Fort  Pitt  foundry,  navy  gun. — The  inspector  in 
his  weekly  report  states  that  one  15-inch  gun  cast  on  the  6th  instant 
has  been  condemned  by  the  founders,  the  gun  having  burst  while  cooling. 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


133 


Reply  to  query  6. 

To  answer  this  would  require  sufficient  time  to  collect  the  facts  from  a 
record  largely  accumulated  during  the  rebellion,  which  the  conveniences 
of  the  committee  does  not  permit.  It  would  include  every  cast-iron  gun 
which  was  proved  or  fired  so  far  as  to  exhibit  cracks  or  signs  of  rupture, 
and  was  then  permitted  to  remain  in  that  condition  without  being  burst. 
I  will  therefore  reply  as  well  as  I  can  to  this  query  in  a  general  way. 

All  fissures  or  cracks  which  appear  inside  or  outside  after  firing  will 
cause  the  rejection  of  any  cast-iron  cannon.  Interior  cracks  may  appear 
in  cast-iron  cannon,  and  will  often  continue  to  extend  for  a  large  number 
of  rounds  before  bursting,  provided  the  metal  is  of  the  least  respectable 
endurance ;  the  line  of  rupture  will  also  in  such  cases  take  the  same 
general  direction,  at  least  in  the  present  models.  But  when  the  metal  of 
the  gun  has  been  very  bad  originally,  or  has  been  rendered  so  by  im- 
proper treatment,  or  by  bad  model,  and  has  no  endurance,  the  gun  will 
break  up  in  fragments  after  very  little  firing. 

The  experience  with  heavy  wrought-iron  cannon  is  not  sufficient  to 
define  the  law  of  fractures  occurring  in  such  material ;  it  may  be  that 
cavities,  cracks,  or  even  fissures,  do  not  imply  a  liability  to  rupture  as 
imminent  or  dangerous  as  in  cast  iron.  But  it  requires  much  experiment 
to  determine  to  what  extent  these  defects  may  extend  without  rendering 
the  gun  unserviceable. 

Wrought-iron  cannon,  like  that  on  the  Princeton,  for  example,  have 
burst  as  suddenly  and  as  fatally  as  guns  of  cast  iron,  and  others  have 
endured  severe  tests  after  the  appearance  and  extension  of  cracks  in  the 
bore. 

The  same  may  be  said  of  some  cast-iron  guns.  The  first  11-inch  gun 
withstood  1,000  rounds  after  it  began  to  crack  inside;  and  the  crack  pene- 
trated entirely  to  the  outer  surface  for  a  length  of  two  feet  in  the  rear 
of  the  trunnions  without  breaking  the  gun  open;  the  next  fire  however, 
did  so. 

I  have  noted  in  replies  to  other  questions  of  the  committee  some 
information  which  might  be  repeated  here,  and  to  which  I  beg  leave  to 
refer.  This  reply  is  very  incomplete,  owing  to  the  want  of  time  to  scruti- 
nize the  reports  of  firing  and  inspection  of  wrought  and  cast  guns. 

Reply  to  query  7. 

1827. — The  regulations  of  this  year  for  naval  ordnance,  "  adopted  by 
the  board  of  navy  commissioners,"  Commodore  Bainbridge,  president, 
prescribe  the  following  for  proof  of  the  heaviest  cannon  by  powder: 


Weight 
of  gun. 

Proof 
charges. 

42-pounder  heavy 

Cwt. 
7U 

Pounds. 
21 

)  Equal  to  one-half 

32-pounder  heavy 

60 

16 

>       the   weight  of 

24-pounder  heavy 

49 

12 

N       solid  shot. 

Each  gun  was  to  be  fired  twice  with  these  charges,  and  two  shot  with 
three  wads,  one  being  placed  over  the  powder,  another  over  the  first  shot, 
and  another  over  the  second  shot. 

If,  after  this  proof,  any  defect  appears  which  occasions  doubt  of  safety 
for  general  service,  this  proof  is  to  be  repeated. 


134  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

1845. — The  next  instructions  concerning  proof  of  "cannon  are  found  in 
the  ordnance  regulations  of  1845,  when  an  entire  reorganization  of 
ordnance  was  adopted,  adopting  one  calibre  for  all  shot  guns — that  of  32 — 
and  fixing  three  classes  of  shell  guns,  a  notice  of  which  will  be  found  in 
my  work  on  "  Shells  and  Shell  Guns." 

In  these  the  Bureau  of  Ordnance  received  discretion  to  have  a  9- 
pounder  cast  as  a  model  gun,  which  was  to  be  proved  as  follows : 

No  of  rounds  20  j  powder  3  pounds ;  shot,  1,  &c.,  &c.,  &c.,  until  the 
gun  breaks. 

The  proof  charges  of  the  heaviest  guns  were  : 


• 

Powder. 

Shot. 

10-inch    10  000  pounds 

Pounds. 

18 

1 

8-inch    10,000  pounds 

18 

2 

8-inch  of  63  hundred  -wei  ght  .  .  ...  .       

18 

1 

8-inch  of  53  hundred-  wei  ght            .           ...                                t 

14 

1 

32-pounder  of  61  hundred-weight 

16 

2 

32-pounder  of  57  hundred-  weight  .       

15 

2 

Each  gun  to  be  fired  twice. 

If  one  gun  in  every  ten  failed  to  sustain  this  proof,  the  remainder 
were  to  be  fired  again  with  the  same  charge  and  one  shot,  if  two  had 
been  used  before,  and  with  three-fourths  the  charge  if  only  one  shot  had 
been  used  before. 

If  one  gun  in  nine  failed  to  stand  this  proof,  all  that  had  been  proved 
were  to  be  rejected. 

The  board  included  Morris,  Warrington,  Crane,  Wadsworth,  and 
Shubrick. 

It  is  presumed  that  this  was  the  usage  is  1850. 

In  1852  a  more  elaborate  series  of  ordnance  instructions  was  promul- 
gated by  the  bureau. 

In  these  the  chief  of  bureau  "may,  if  lie  thinks  proper,  have  a  trial 
gun  cast  therefrom*  which  shall  be  subjected  to  such  proof  as  he  may 
direct  and  specify  in  the  contract." 

The  proofs  were  to  be : 


Powder. 

Shot. 

10-inch  of  10  000  pounds 

Pounds. 

18 

1 

8-inch  of  63  hundred-weight  

16 

] 

8-inch  of  55  hundred-  weight  .           .  

14 

1 

64-  pounder  of  106  hundred-  weight           ..   ...  

20 

2 

32-pounder  of  6J  hundred-weight                                                               

16 

2 

32-pounder  of  57  hundred-weight  

15 

2 

Each  gun  to  be  fired  twice. 

First.  It  will  be  observed  that  it  still  remained  discretionary  with 
the  chief  of  bureau  to  order  a  trial  gun  or  not. 

Second.  That  he  was  restricted  in  kind  or  size  as  before. 

Third.  That  the  proof  of  the  8-inch  of  6,300  pounds  was  reduced  from 
18  pounds  to  16  pounds  5  that  the  8-inch  of  10,000  pounds  disappeared 
and  was  replaced  by  the  heavy  64-pounder,  (an  8-inch  cannon,)  of  10,600. 

*Iron  offered  by  contractors. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          135 

It  is  to  be  supposed  that  this  continued  to  be  the  proof  in  1855. 

The  officers  of  the  board  were,  Farragut,  Dornin,  Barren,  Harwood, 
Fairfax — Commodore  Morris,  chief  of  bureau. 

In  1860  the  ordnance  instructions  were  revised.  No  directions  are 
given  in  regard  to  the  inspection  and  proof  of  cannon. 

The  9-inch,  10-inch,  and  11-inch  of  my  design  are  there  announced  as 
part  of  the  regular  armament. 

The  officers  of  the  board  were,  Goldsborough,  Harwood,  Lee,  and  Fair- 
fax— Captain  In  graham,  chief  of  bureau. 

1864. — First.  The  instructions  of  this  date  give  discretion  to  the  bureau 
before  contract,  to  order  a  trial  gun  for  extreme  proof  with  service  charge. 
This  gun  was  to  serve  as  a  standard  for  metal  to  be  used. 

Second.  "But  whether  a  trial  gun  was  made  or  not,"  the  chief  of 
bureau  might  select  "for  extreme  proof  with  service  charges,"  one  out  of 
any  lot  of  guns  offered  under  contract. 

Third.  Proof  charges :  Fifteen-inch,  No.  1,  50  pounds,  cored  shot ;  No. 
10,  35  pounds,  shell. 

Eleven-inch,  No.  1,  25  pounds,  shot ;  No.  10,  15  pounds,  shell. 

Ten-inch,  No.  1,  18  pounds,  shot ;  No.  10,  12  pounds,  shell. 

Nine-inch,  No.  1,  15  pounds,  shot ;  No.  10,  10  pounds,  shell. 

Eight-inch,  6,300  pounds,  No.  1,  12  pounds,  shot  j  No.  10,  10  pounds, 
shell. 

One-hundred-and-thirty-pounder  of  16,000  pounds,  No.  10,  30  pounds, 
one  shot. 

Sixty-four-pounder  of  10,600  pounds,  No.  10,  20  pounds,  one  shot. 

Thirty- two-pounder  of  5,700  pounds,  No.  10,  15  pounds,  one  shot. 

If  five  per  cent,  out  of  any  lot  offered  for  ordinary  proof  under  a  con- 
tract shall  fail  to  sustain  it,  the  whole  may  be  rejected,  as  may  be  stipu- 
lated in  the  contract.  These,  it  is  presumed,  were  the  rules  in  1865. 

1866. — The  instructions  of  this  year  fix  the  proof  charges  as  follows : 

Fifteen-inch,  No.  3,  35  pounds,  shell ;  No.  3,  45  pounds,  shell  ;  No.  3, 
55  pounds,  cored  shot. 

As  in  1864,  the  failure  of  five  per  cent,  in  a  lot  gave  discretion  to  reject 
all.  The  instructions  of  each  date  are  to  be  accepted  as  a  recognition  of 
the  operations  and  practice  then  adopted. 

The  practice  of  proving  cannon  by  increased  charges  of  powder  and 
shot  prevailed  prior  to  1827,  and  continued  to  1845,  with  the  addition,  at 
the  latter  date,  of  a  trial  gun  of  9  pounds  calibre,  proved  previously  by 
specified  charges  5  and  this  was  the  only  improvement  on  the  previous 
system  $  and  this  was  not  enjoined,  but  was  discretionary. 

1852. — In  1852  the  trial  gun  was  still  retained  as  discretionary  with  the 
bureau,  and  no  calibre  being  assigned,  that  too  thus  became  discretion- 
ary also,  so  that  he  was  empowered  to  have  the  trial  gun  of  any  calibre, 
and  to  prove  it  in  any  way  he  thought  proper. 

I860. — In  the  instructions  of  1860  all  mention  of  proof  or  inspection  is 
omitted.  Important  changes  had  taken  place.  Our  new  screw  frigates 
and  sloops  were  armed,  according  to  my  own  system,  with  Dahlgren 
9-inch,  10-inch,  and  11-inch  guns,  and  these  guns  are  given  in  the  instruc- 
tions as  of  regulation.  In  fact,  with  these,  other  views  of  proof  had  come. 

I  had  always  been  opposed  to  the  principle  of  proving  any  gun  with 
more  than  a  service  charge.  The  proof  gun  was  always  to  be  one  of  the 
kind  to  be  proved,  and  its  proof  was  to  be  service  charges  till  burst. 

The  ordinary  proof  for  each  gun  might  be  a  small  number  of  service 
charges,  10  or  20,  but  the  bureau  still  retained  a  large  number  of  guns  of 
the  old  system  in  service,  and  hesitated  to  apply  my  views  to  it ;  so 
nothing  was  said,  which  may  be  the  explanation. 


136  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

1864. — This  year  my  own  views  are  accepted.  The  bureau  was  author- 
ized to  use  a  trial  gun  to  fix  the  standard,  and  also  to  select  a  gun  from 
a  lot  for  extreme  proof,  with  service  charges. 

In  addition,  as  the  question  of  hammering  plating  was  presented,  and 
the  guns  were  to  use  higher  charges,  therefore  the  ordinary  proof  added 
one  service  charge  of  that  description. 

1866. — The  same  is  retained,  except  with  15-inch  guns. 

The  proof  to  extreme,  being  at  the  discretion  of  the  bureau,  has  been 
fixed  at  1,000  rounds  (service)  in  the  contracts. 

Reply  to  query  8. 

It  would  be  impossible  for  me  to  answer  this  question  fully  and  cor- 
rectly within  the  very  limited  time  which  the  convenience  of  the  com- 
mittee permits,  as  it  would  necessitate  the  close  examination  of  a  large 
number  of  log-books,  besides  the  numerous  records  of  this  bureau. 

I  will  only  be  able  to  submit  a  few  desultory  and  disconnected  facts, 
premising  that  they  are  insufficient  to  form  a  proper  opinion. 

When  the  first  15-inch  gun  was  being  put  through  a  course  of  proof- 
firing  I  was  absent,  or  too  closely  occupied  with  other  duties  to  be  present. 
The  record  is  very  general,  noting  only  the  principal  facts. 

While  in  command  of  the  South  Atlantic  squadron  I  was  frequently 
on  board  the  monitors  in  action,  and  therefore  witnessed  the  general 
character  of  the  firing,  but  my  attention  was  always  too  closely  taken  up 
by  passing  events  to  time  the  rate  of  fire.  The  impressions  on  my  mem- 
ory are  that  it  required  five  to  six  minutes  for  each  shot  from  a  15-inch 
gun,  and  this  is  all  that  I  can  say  with  reference  to  the  rapidity  of  fire 
that  was  attained  in  action  by  15  inch  guns  of  monitors,  mounted  on  the 
carriages  in  their  turrets,  the  machinery  of  which  was  worked  by  hand. 

In  the  spring  of  1868  a  15-inch  gun  was  tried  upon  a  carriage  worked 
by  steam,  after  the  design  of  Mr.  Eads.  The  most  rapid  fire  was  the 
discharge  of  12  shot  in  16  minutes,  making  an  average  interval  of  one 
minute  and  20  seconds  between  the  fires,  which  is  certainly  an  excellent 
result ;  one  interval  was  as  small  as  58  seconds.  Still  it  cannot  be  com- 
pared with  the  result  of  ordinary  fire  in  action  cited  previously,  because 
there  was  a  very  essential  difference  in  the  circumstances. 

When  fired  ^irom  the  monitor  turret  the  15-inch  gun  was  not  only 
loaded,  but  the  turret  was  revolved  from  the  object,  then  back  upon  the 
object,  to  which  it  had  to  be  adjusted  by  one  person  who  did  not  see  the 
object,  but  received  direction  from  another  who  did  see  it,  yet  very  imper- 
fectly, through  a  tube  at  the  side,  and  was  also  delayed  by  the  swaying 
of  the  vessel,  whether  at  anchor  or  under  way ;  all  of  which,  under  the 
most  favorable  circumstances,  would  occupy  at  least  half  of  the  five  or 
six  minutes. 

On  the  other  hand,  the  interval  of  one  minute  and  20  seconds,  accom- 
plished by  the  steam  apparatus  and  carriage,  only  denoted  the  time 
required  to  load  and  fire ;  the  carriage  was  placed  on  a  scow ;  the  gun 
horizontal,  and  not  pointed. 

The  difference  between  firing  in  service  and  in  experiment  is  also  con- 
siderable, even  where  circumstances  are  otherwise  similar.  On  one  occa- 
sion a  9-inch  gun  was  fired  from  the  experimental  battery  four  times, 
with  an  average  interval  of  53  seconds ;  least,  45 £  seconds.  On  another 
a  9:inch  gun  of  the  experimental  battery  was  fired  six  times ;  average 
interval,  38J  seconds ;  the  least,  32  seconds.  In  another  instance  in  exper- 
iment, an  11-inch  gun  was  worked  by  eight  men  and  fired  twice,  the 
interval  being  61  seconds.  But  this  rate  of  fire  with  such  cannon  would 
not  be  possible  in  action. 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


137 


On  the  whole,  I  have  no  doubt  the  15-inch  gun  can  be  fired  more 
rapidly  on  the  steam  carriage  than  on  one  worked  by  hand,  but  what 
that  difference  is,  how  far  to  be  relied  on  with  certainty,  and  at  what 
cost  in  other  advantages,  experiment  alone  will  show,  and  should  be  made 
to  show. 

Reply  to  query  9. 

The  navy  has  never  used  a  Parrott  10-inch  rifle.  I  have  no  informa- 
tion as  to  the  rapidity  of  fire  with  Parrott  8-inch  rifles.  In  general,  more 
time  is  required  to  load  a  rifle-cannon  of  large  calibre  than  a  smooth-bore, 
the  weights  of  shot  and  charge  being  alike. 

Reply  to  query  10. 

All  the  information  upon  this  subject  that  can  be  reached  within  the 
time  admissible  to  prepare  this  paper  has  been  given  in  the  reply  to 
query  8. 

Reply  to  query  11. 

THE  NAVY  15-INCH   GUN. 

There  being  two  classes  of  the  navy  15-inch  gun — the  short  and  the 
long — and  a  large  proportion  of  the  original  cannon  made  after  my 
draught  having  been  altered,  the  question  of  the  committee  will  be  best 
answered  perhaps  in  the  following  way: 

The  navy  15-inch  guns  may  be  classed  thus :  1.  The  original  15-inch 
designed  by  myself.  2.  Guns  of  the  same  class,  subsequently  altered  by 
order  of  the  bureau.  3.  The  new  model  15-inch,  got  up  by  direction 
of  the  bureau. 

The  original  navy  15-inch  was  designed  by  myself,  and,  conformably  to 
the  wishes  of  Captain  Ericsson,  was  restricted  to  such  length  as  would 
permit  it  to  be  fired  inside  the  turret. 

Thirty-four  guns  were  made  in  accordance  with  this  design,  one-half 
of  which  were  subsequently  increased  in  the  chamber  and  decreased 
outside  at  the  chase  by  order  of  the  bureau. 

Of  the  16  15-inch  which  were  not  altered  but  remained  as  designed 
by  me,  the  service  of  two  is  only  known  to  have  been  very  good,  one 
having  been  lost  in  the  Weehawken,  and  the  other  sold  from  the  Lehigh. 

The  remaining  14,  with  the  proof  gun,  endured  3,152  fires,  averaging 
210  rounds,  the  greatest  being  (No.  1)  622,  and  the  next  529. 

Of  the  17  15-inch  guns,  made  after  my  design  and  not  altered  therefrom, 
the  proof  gun  was  burst  by  868  charges,  and  three  were  injured  prema- 
turely by  service  firing,  viz : 

ORIGINAL   15-INCH,    (SHORT.) 


No. 

Rounds  fired. 

On  board. 

'Condition 

. 

19 

132 

Onondasra          -•                       ......          .... 

Cracks  at  vent. 

13 

Unknown 

Lehigrh                     .                           

Muzzle  cracked, 

(sold.) 

14 

96 

Onondaga 

Cracks  at  vent. 

Seventeen  other  15-inch  guns  of  my  model  were  altered  by  the  bureau 
by  reaming  out  the  chamber  and  reducing  the  chase.  They  have  been 
fired  in  all  2,266  times,  averaging  135  fires,  the  greatest  being  (No.  34) 
363  fires,  and  the  next  (No.  23)  358 ;  both  are  reported  to  be  in  doubtful 
condition. 


138 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


Of  the  whole  number,  eight  have  been  more  or  less  injured  by  firing, 
as  follows,  viz : 


No. 

No.  of  fires. 

On  board. 

Condition. 

19 

351 

Reports  contradictory. 

0^ 

358 

Cauonicus 

Reports  contradictory. 

*M 

168 

Monadnock 

Excessive  wear  (sold  ) 

05 

9 

Sold  at  auction 

Cracks  at  vent 

k>6 

9 

Sold  at  auction           .................    .... 

Cavities  in  chamber. 

07 

161 

Monadnock           .          .....                  .     ... 

Condemned,  (sold.) 

oq 

243 

Sauo*us 

Burst  at  chase  Fort  Fisher. 

31 

363 

Doubtful 

As  a  memorandum  before  your  committee  has  given  the  reasons  for 
altering  my  design  of  the  navy  15-inch  gun,  I  presume  it  is  admissible 
for  me  to  examine  how  far  these  reasons  are  sustained  by  the  evidence 
given. 

The  memorandum  says,  (Heavy  Ordnance,  page  129,)  that — 

It  was  found  necessary  to  reduce  the  opening  of  the  ports  in  the  turrets  as  much  as  possi- 
ble, and  to  permit  the  muz/le  of  the  gun  to  protrude  through  them,  thus  doing1  away  with 
the  troublesome  smoke-box  hitherto  used,  and  which  was  indispensable  with  the  shortened 
15-inch  gun  originally  designed. 

During  this  dilemma  it  also  became  apparent,  from  repeated  results  with  the  "  teat  cham- 
ber," that  it  was  not  only  most  inconvenient  in  service,  but  it  really  hastened  the  rupture  of 
the  gun  instead  of  preventing  it. 

It  thus  became  necessary  to  act,  and  promptly  too. 

Therefore  the  present  Chief  of  the  Ordnance  Bureau  ad  interim  directed  the  first  15-inch 
cast  for  the  navy,  and  which  was  then  undergoing  a  series  of  experimental  firing  at  the  ord- 
nance yard,  in  this  city,  to  be  placed  upon  the  lathe,  the  teat  chamber  reamed  out,  so  as  to 
leave  a  chamber  nearly  parabolic  in  form,  and  to  reduce  the  diameter  of  the  chase  and  muz- 
zle to  correspond  with  that  of  the  model  of  the  13-inch  gun. 

The  result  was  most  satisfactory;  the  gun  enduring  heavy  charges  of  50,  60,  and  two  of 
70  pounds  of  ordinary  cannon  powder,  with  shells  and  shot,  the  latter  weighing  440  pounds, 
and  did  not  give  way  until  it  had  reached  nearly  900  rounds. 

The  order  was  immediately  given  to  rechamber  and  turn  down  in  the  same  way  all  the 
original  15-ineh  guns,  and  to  cast,  as  soon  as  possible,  a  lot  of  these  guns  on  the  new  pat- 
tern. 

Now  the  facts  of  the  case  may  be  summed  thus : 

1st.  The  first  15-inch  gun,  as  I  designed  it,  was  fired  622  times,  with 
charges  varying  from  30  pounds  of  mammoth  powder  to  50  pounds  of 
cannon  powder. 

2d.  After  this  the  teat  chamber  and  vent  were  reported  to  show  only  the 
usual  wear. 

3d.  The  teat  chamber  was  then  reamed  out  to  a  parabolic  form  by  order 
of  the  bureau,  and  the  extremity  of  the  chase  reduced  in  diameter  to 
that  of  a  13-inch  gun. 

4th.  The  firing  was  resumed  and  carried  to  246  rounds,  with  charges 
varying  from  45  pounds  of  mammoth  to  70  pounds  of  cannon.  At  the 
246th  fire  the  gun  burst.  (See  reply  to  query  3.) 

The  Ordnance  Bureau  deemed  this  result  so  satisfactory  that  it  ordered 
all  the  15-inch  guns  at  hand  to  be  reamed  out  and  reduced  as  the  proof 
gun  had  been. 

Was  this  action  of  the  bureau  in  altering  the  15-inch  warranted  by 
the  facts  of  the  case  f 

The  bureau  makes  its  reasons  for  altering  the  model  to  rest  on  the 
premise  that  the  teat  chamber  hastened  the  rupture  of  the  gun. 

Now  does  this  appear  to  have  been  justified  when  the  teat  chamber 
was  perfectly  sound  after  622  fires,  and  no  sign  was  then  perceived  indi- 
cating rupture,  or  even  weakness  ? 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          139 

If  either  chamber  is  chargeable  with  the  hastening  the  rupture  of  the 
gun  it  must  have  been  the  parabolic,  for  with  that  the  gun  gave  way 
after  246  rounds. 

The  true  conclusion  after  622  fires  was  that  a  gun  which  endured  so 
well  ought  not  to  have  been  altered  at  all,  but  should  have  been  tested 
to  the  end  in  its  original  construction,  and  no  "change  was  warranted 
even  in  the  other  guns  that  had  been  cast,  unless  the  extreme  proof  of 
another  gun  of  the  class  had  shown  better  endurance,  and  there  was 
sufficient  reason  to  believe  this  to  be  due  to  the  alteration  that  had  been 
adopted,  whether  in  chamber  or  elsewhere. 

Is  not  this  view  fully  sustained  by  the  subsequent  results  with  these 
15-inch  guns,  altered  and  unaltered  I  Of  the  17  on  the  original  model 
only  three  were  unserviceable  after  firing  3,152  rounds.  Of  the  17  that 
were  altered,  eight  were  unserviceable  after  firing  2,296  rounds. 

To  my  mind  there  is  but  one  conclusion  possible  :  my  original  design 
was  not  improved  by  the  alteration  made  by  order  of  the  bureau,  in  the  guns 
that  were  cast,  but  was  injured  thereby. 

Let  us  now  consider  the  other  question  which  forced  itself  upon  the 
consideration  of  the  authorities.  The  memorandum  says : 

It  was  found  necessary  to  reduce  the  opening  of  themports  in  the  turrets  as  much  as  possible, 
and  to  permit  the  muzzle  of  the  gun  to  protrude  through  them,  &c. 

The  reading  of  this  does  not  seem  to  express  what  it  really  intends, 
which  I  understand  to  be,  the  firing  from  the  inside  of  the  turret  was 
found  to  be  so  troublesome  in  service  by  reason  of  the  smoke  box,  which 
was  indispensable  to  the  practice,  as  to  make  it  necessary  to  pass  the 
gun  through  the  turret  5  but  as  the  chase-diameter  of  the  15-inch 
would  require  too  large  an  aperture  for  this  purpose,  it  was  reduced,  and 
the  original  model  was  altered,  increasing  the  length  of  the  gun,  and 
reducing  the  diameter  of  the  chase  to  that  of  a  13-inch  gun,  by  which 
improvement  the  thickness  at  muzzle  was  reduced  from  the  original  five 
and  three-quarter  inches  to  three  inches  ;  very  little  more  than  one-half 
of  what  I  considered  necessary  for  the  incidents  of  service.  There  were 
66  15-inch  guns  cast  upon  this  pattern.  The  first  gun  was  chosen  for 
proof;  it  endured  131  fires,  after  which  Commander  Breese  reported  it 
to  be  doubtful.  Of  the  remaining  65,  42  have  been  fired  only  the  proof 
rounds,  now  fixed  at  nine.  Twenty-five  have  been  mounted  in  iron- 
clads, and  been  subjected  to  such  firing  as  the  course  of  service  required, 
amounting  to  a  total  of  1,333  fires ;  making  an  average  of  53  fires  for 
each  gun ;  greatest  number  (No.  43)  236  fires  j  (No.  37)  206  fires.  Of 
these  25,  four  have  been  injured,  viz : 


No. 

No.  of 
rounds. 

Where  fired. 

Condition. 

35 

131 

Proof                            .         .                  

Doubtful 

44 

85 

Mahopac            .                           ......       ....... 

Ohase  split 

67 

102 

Puritan.                                                        - 

Cracks  about  vent,  (sold.) 

68 

59 

Trial  of  carriage 

Cracks  about  vent  (sold.  ) 

So  that  the  original  model  lost  only  one-fifth  of  its  number  after  its 
17  guns  had  been  fired  3,152  times. 

An  equal  number  of  original  guns,  after  being  altered,  lost  nearly  one- 
half  their  number,  though  fired  but  three-fourths  as  often  as  the  same 
number  of  original  guns. 

The  new  model  (long  15 -inch)  lost  one-fourth  of  its  number,  or  nearly 
an  equal  proportion  as  the  original  model,  though  only  subjected  to  two- 
fifths  the  firing,  (less  than  one-half.) 


140  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

The  foregoing  statements  show  that  the  substitution  of  a  new  cham- 
ber, and  a  reduction  of  the  chase,  in  the  original  guns  were  detrimental 
to  the  strength  of  the  guns ;  they  also  show  that  the  new  model  was  not 
to  be  trusted  in  service. 

All  the  difficulties  noted  in  the  foregoing  arose  from  pursuing  a  wrong- 
direction  in  the  first  instance. 

The  department  was  advised  that  under  existing  circumstances  a 
smaller  calibre  than  that  of  15-inch  was  prefer  able,  and  that  of  13-inch 
was  suggested.  The  15-inch  was,  however,  adhered  to,  and  the  first 
consequence  was  to  be  met  at  the  threshold;  the  chase  diameters  of  the 
15-inch  were  so  great  that  it  was  found  inadmissable  to  open  a  point  in 
the  side  of  the  turret  sufficiently  large  to  admit  of  the  muzzle  passing 
outside. 

To  obviate  this  it  was  necessary  to  abut  the  muzzle  on  the  inner  sur- 
face of  the  turret,  and  to  .make  an  aperture  in  the  turret  only  large 
enough  for  the  passage  of  the  ball. 

The  first  firing  showed  that  the  smoke  would  not  be  endurable  when 
the  gun  was  fired  in  this  way ;  the  muzzle  was  therefore  boxed,  which 
proved  effective ;  but  it  was  soon  found  that  the  box  was  liable  to  give 
way  continually  before  the  great  concussion  of  firing,  even  with  the  very 
moderates  charge  used. 

The  inside  firing  had  therefore  to  be  abandoned,  and  a  port  opened, 
but  to  make  this  possible  the  chase  diameter  must  be  reduced  ;  and  so, 
instead  of  falling  back  on  a  proper  calibre,  the  size  of  which  would  not 
require  too  large  a  port  for  firing  outside,  it  was  determined  to  reduce 
the  chase  of  the  15-inch. 

This  resulted  in  altering  the  guns  of  original  model,  and  in  the  casting 
of  others  upon  a  new  model ;  the  consequences  of  which  have  been 
shown  to  be  highly  injurious  to  the  endurance  of  these  15-inch  guns, 
if  not  absolutely  destructive  of  their  reliability. 

The  memorandum  argues  against  the  adoption  of  the  13-inch  gun, 
(page  131,)  from  the  failure  of  those  tried,  the  want  of  time  for  experi- 
ment, the  necessity  of  firing  outside,  &c. 

1st.  Whatever  were  the  defects  of  the  inside  firing,  it  was  well  estab- 
lished by  the  long-continued  service  off  Charleston  that  it  could  be  con- 
tinued in  any  further  service  for  which  the  monitors  might  be  required. 

If  therefore  the  15-inch  was  to  be  adhered  to,  it  was  better  to  fire 
inside  and  to  take  the  chances  of  the  smoke-box  than  to  reduce  the  chase 
to  an  untrustworthy  diameter. 

2d.  There  was  quite  as  much  time  to  correct  errors  in  the  founding  of 
13-inch  as  there  was  to  experiment  with  the  15-inch,  which  the  altera- ' 
tions  really  amounted  to. 

These  errors  were  obvious,  and  needed  only  correcting,  not  experiment.  It 
has  been  a  primary  principle  in  making  cast-iron  cannon  that  the  larger 
the  cannon  the  less  was  the  probability  (I  might  say  the  certainty)  of  its 
endurance.  Therefore  if  a  15-inch  gun  could  be  made  strong  enough 
for  service,  a  smaller  gun  like  the  13-inch  would  be  much  more  so,  and  a 
contrary  result  proved  errors  in  the  fabrication,  the  models  being  alike. 

The  data  cited  by  the  memorandum  point  to  this,  and  even  with  an 
error  that  exists  in  these  data  they  should  be  conclusive ;  for  instance, 
the  memorandum  states  that  one  of  these  13-inch  "  did  not  give  way  at 
500  rounds." 

Kow  the  entire  actual  service  of  the  15-inch  shows  that  only  one  gun 
of  this  kind  was  fired  more  than  360  times,  and  that  one  gun  went  as  far 
as  529  fires ;  perhaps  in  no  case  did  the  charges  exceed  35  pounds  of 
powder,  while  the  13-inch  was  fired  with  charges  of  50  pounds.  It  is 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          141 

further  to  be  remarked  that  these  13-inch  guns  were  made  at  a  foundry 
which  for  the  first  time  essayed  the  process  of  hollow  casting,  and  could 
hardly  be  expected  to  attain  entire  success  at  the  outset. 

It  seems  to  me  that  there  was  every  assurance  in  this  single  result  to 
show  that  13-inch  guns  cast  with  as  much  care  and  experience  as  the 
15-inch,  would  have  more  endurance  than  the  15-inch,  while  the  size  of 
the  chase  would  need  no  greater  size  of  port  than  was  actually  given  to 
the  reduced  15-inch.  This  course  risked  far  less  than  that  pursued  by 
the  bureau,  which  was  an  experiment  against  probabilities. 

The  memorandum  also  goes  beyond  the  question  of  calibres  with  its 
incidents,  and  enters  upon  the  question  of  solid  and  hollow  casting, 
taking  for  its  premises  certain  data,  which,  even  correctly  given,  would 
not,  I  think,  lead  to  the  conclusions  of  the  memorandum,  because  the 
foundry  at  Providence  was  entirely  without  experience  in  casting  cannon 
of  any  size,  and  its  results  were,  therefore,  not  to  be  compared  with  those 
of  another  foundry,  where  the  experience  of  years  had  been  accumulated 
under  special  directions. 

On  the  contrary,  I  will  affirm,  from  my  own  long  experience,  that  the 
result  at  Providence  was  eminently  successful.  To  make  a  solid  casting 
of  a  13-inch  gun  so  well  the  first  time  that  it  stood  178  fires,  is  to  me  an 
assurance  of  entire  success  with  more  experience  ;  but  an  important  error 
is  made  by  the  memorandum  in  stating  that  the  13-inch  gun  cast  at 
Pittsburg  was  cast  solid.  It  was  cast  hollow,  and  with  all  the  lights  of 
a  long  experience,  yet  it  gave  way  at  108  fires. 

Shall  we  infer  from  these  facts  that  a  13-inch  gun  could  not  be  made 
as  endurable  as  a  15-inch,  the  processes  and  the  models  being  alike  ? 

Shall  we  infer  that  the  experienced  founders  at  Pittsburg  could  only 
make  a  hollow-cast  13-inch  to  stand  108  fires,  when  foundries  inexpe- 
rienced in  hollow  casting  could  make  a  13-inch,  also  hollow-cast,  that 
would  not  burst  at  500  fires  ? 

Shall  we  infer  that  the  Pittsburg  gun,  cast  after  the  hollow  method  so 
highly  extolled,*  (page  88,  Heavy  Ordnance,)  would  only  endure  108 
fires,  when  another  of  like  model  cast  solid,  by  a  founder  who  had  never 
done  such  work  before,  would  only  burst  at  178  fires  ?  Certainly  not  ; 
yet  these  would  be  the  inferences,  from  the  premises  given  and  corrected, 
of  the  memorandum. 

On  the  whole  I  am  unable  to  perceive  that  it  was  advisable — first,  to 
select  the  15-inch  for  the  monitors ;  secondj  to  alter  it,  as  was  done,  when 
it  had  been  chosen  ;  and  I  think — first,  that  the  13-inch  gun  was  prefer- 
able because  it  could  have  been  made  more  enduring  than  the  15-inch 
was,  not  too  large  to  permit  its  being  fired  outside,  and  had  sufficient 
power  (50  pounds  and  shot  of  280  pounds)  to  penetrate  any  plating 
opposed  to  us  by  the  rebel  rams ;  second,  that  when  the  probable  incon- 
venience of  the  15-inch  had  been  realized  in  service,  the  reasons  for  sub- 
stituting the  13-inch  became  imperative,  instead  of  retaining  the  15-inch 
and  lessening  such  usefulness  as  it  may  have  possessed  by  alteration. 

*  Mr.  Knap  said: 

I  would  say,  as  my  opinion  as  a  manufacturer,  and  from  my  examination  of  these  guns,  that  there  is  not 
known  any  method  of  procuring  the  same  efficiency  at  the  same  cost  and  the  same  risk  to  life  of  your  own 
men,  as  the  heavy  ordnance  cabt  upon  the  Rodman  principle.  You  may  take  a  cast-iron  gun  or  wrought-iron 
gun,  or  anything  else  of  very  heavy  calibre,  and  I  will  be  willing  to  haug  my  gun  alongside  of  it  and  let  them, 
be  fired,  aud  if  mine  fails  before  the  others  do  I  will  give  up. 


142 


EXPEEIMENTS    ON    HEAVY    ORDNANCE. 


PARROTT  RIFLE   GUNS  DISABLED. 


Calibre. 

Register 
number. 

Vessel. 

Remarks. 

100-pound  er 

2 

Hunchback 

Burst  23  inches  from  muzzle  June  19, 

Do 

4 

Westfield 

4864. 
Burst  at  breech  and  opened  band   in 

Do 

6 

Mahaska 

several  places,  October  31,  1862. 
Thirty-six  inches  of  muzzle  burst  off; 

Do  

11 

Commodore  Barney... 

date  unknown. 
Muzzle  burst  off;    shell  exploded  in 

Do 

18 

Genesee 

gun,  April  JO,  1862. 
Cracked  in  rear  of  bouching  May,  1864. 

Do 

21 

Cimarron 

Burst  2"<i-J  inches  from  muzzle    Feb- 

Do. 

24 

Paul  Jones   ...... 

ruary  15,  1864. 
Burst,  fracture  from  trunnion,  to  rear 

Do 

05 

Sassacus 

of  band,  July  18,  1863. 
Cracked  ;  two  cracks  at  vent    Janu- 

Do  

29 

Juniata   ..... 

ary,  1865. 
Burst  ;  rear  part  flew  out,  December 

Do 

44 

Commodore  Perry 

25,  1864. 
Burst  at  breech  June  17   1864 

Do  

135 

Fort  Jackson 

Cracked  at  vent  January  14,  1865. 

Do 

137 

Quaker  City 

Burst  two  and  a  half  feet  of  muzzle  off, 

Do  

141 

Mackinaw  ....... 

December  24,  18(54. 
Burst  ;    breech  blown  out,  December 

Do 

149 

Commodore  Read 

26,  1864. 
Cracked  in  top  of  bore  and   around 

Do  

150 

Commodore  Read. 

breech,  November  14,  1864. 
Cracked   at  bouching,  November   14, 

Naugatuck  .  

1864. 

Burst. 

Do  

162 

Ticonderoga.  ..... 

Burst  at  muzzle,  November  14,  1864. 

Do  

166 

Yautic  . 

Burst  ;    breech  blown  out,  December 

Do 

194 

Maumee 

24,   1864. 
Cracked  through  vent  January  1865. 

Do  

213 

Kansas  ... 

Cracked  at  vent,  December  24,  1864. 

Do  

233 

Osceola 

Cracked  ;    two   cracks   from   band   to 

Do  

238 

Mendota  .....    . 

trunnion,  January  15,  1865. 
Cracked  from  trunnion  to  band,  July 

Do  

262 

Tallapoosa 

24,  1864. 
Muzzle  blown  off  by  premature  explo- 

Do   

288 

Mohican 

sion  of  shell,  April  5,  1865. 
Burst,  December,  1864. 

Do  

311 

Ticonderoga 

Burst  into  10  pieces     December  24 

Do 

325 

Lenape 

1864. 
Cracked  through  vent  Februarv  1865 

Do  

330 

Lenape              .... 

Cracked  through  vent,  February,  1865. 

150-pounder 

6 

Patapsco 

Slight  crack  at  muzzle   July  22,  1863 

Do 

28 

Shenandoah 

Crack  in  rear  of  vent  extending  around 

Do... 

46 

Onondaga 

breech,  February,  1865. 
Two  cracks  in  bore. 

Do  

59 

Pequot 

Burst  three  feet  ten  inches  from  muzzle 

Do  

60 

Colorado 

September  12,  1864. 
Seam  from  trunnion  to  band   Decent- 

Do  

61 

Onondaga 

ber25,  1864. 
Cracked  at  vent,  April,  1865 

Do  

82 

Susouehanna 

Burst  ;  piece  of  muzzle  blew  out  June 

15,  1865. 

TRIAL   GUN  AT   CASTLE  ISLAND,   NOVEMBER,   1862. 

Four  hundred  and  twenty  rounds;  charges  15  pounds  of  powder. 
Shot:  Schenkl,  194 J  pounds ;  Parrott,  17?|  pounds ;  Hotchkiss,  199  J 
pounds. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          143 

WIARD'S  15-iNCH  SMOOTH-BORE,  (CAST  IRON.) 

The  first  and  only  gun  fired  of  this  description  burst  June  4,  1864,  at 
the  first  proof-fire ;  charge  80  pounds  of  powder,  and  shot  of  880 
pounds. 

ERICSSON  12-INCH  SMOTH-BORE   (WROUGHT  IRON.) 

The  Ericsson  (13-inch  smooth-bore  of  wrought  iron)  was  fired  Octo- 
ber, 1864,  40  times,  viz : 

Two  charges  of  30  pounds  of  powder,  shot  280  pounds ;  five  charges 
of  35  pounds  of  powder,  shot  280  pounds ;  five  charges  of  40  pounds  of 
powder,  shot  280  pounds ;  five  charges  of  35  pounds  of  powder,  shot  280 
pounds  ;  five  charges  of  50  pounds  of  powder,  shot  280  pounds ;  five 
charges  of  55  pounds  of  powder,  shot  280  pounds  ;  five  charges  of  60 
pounds  of  powder,  shot  280  pounds  ;  two  charges  of  65  pounds  of  pow- 
der, shot  280  pounds ;  three  charges  of  70  pounds  powder,  shot  280 
pounds ;  three  charges  of  75  pounds  powder,  shot  280  pounds.  Gun 
unserviceable. 

12-INCH  RIFLES. 

These  were  castings  on  the  exterior  form  of  15-inch  guns ;  bored  to 
12-inch  and  rifled.  The  order  was  given  August  31,  1863,  by  Captain 
Wise,  then  chief  of  bureau.  One  of  these  was  rifled  on  Mr.  Parrottfs 
plan,  'one  on  Atwater's,  and  one  on  Rodman's. 

The  12-inch  rifled  on  Mr.  Parrott's  method  burst  at  the  27th  fire,  viz  : 

Five  charges  of  35  pounds  of  mammoth  powder  ;  five  charges  of  40 
pounds  of  mammoth  powder ;  five  charges  of  45  pounds  of  mammoth 
powder ;  five  charges  of  50  pounds  of  mammoth  powder ;  five  charges 
of  35  pounds  of  No.  7  cannon  powder ;  one  charge  of  40  pounds  of  No.  7 
cannon  powder  ;  three  charges  of  45  pounds  of  No.  7  cannon  powder. 

The  12-irich  gun,  rifled  on  General  Rodman's  method,  was  badly 
cracked  by  16  fires,  viz  : 

Three  charges  of  mammoth  powder,  35  pounds;  three  charges  of 
mammoth  powder,  40  pounds;  four  charges  of  mammoth  powder,  45 
pounds;  four  charges  of  mammoth  powder,  50  pounds;  one  charge  of 
mammoth  powder,  35  pounds;  one  charge  of  mammoth  powder,  40 
pounds. 

Shot,  618  to  619  pounds.     Gun  cracked ;  firing  stopped. 

The  third  12-inch  rifled,  on  Atwater's  plan,  burst  at  the  30th  fire ; 
generally  55-pound  charges ;  and  shot  varying  from  416  to  535  pounds. 

The  practice  was  conducted  at  Fort  Monroe  by  the  army  ordnance, 
(1867.) 

DAHLGREN  150-POUNDERS. 

Only  three  of  these  were  tested,  and  their  accuracy  was  excellent, 
but  the  iron  was  not  of  sufficient  endurance,  therefore  never  put  into 
service.  One  was  burst  in  proof  at  the  27th  fire  ;  one  was  fired  20  rounds ; 
one  was  fired  75  rounds ;  one  was  fired  60  rounds. 

They  remained  unbroken ;  but  as  I  was  not  satisfied  with  the  iron, 
they  were  never  put  into  service,  and  the  pressing  events  of  the  war  cut 
short  my  connection  with  the  subject. 


144  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Reply  to  query  12. 

The  following  150-pounder  cannon,  and  larger  smooth-bore  and  rifled 
guns,  have  been  the  subject  of  proof  or  experiment  in  the  navy: 

1.  The  150-pounder  Parrott ;  the  Dahlgren  150-pounder;  the  Bureau 
600-pounder,  (42-inch  bore;)  the  Mann  breech-loader,  8-inch;  the  Erics- 
son 13-inch ;  the  Wiard  15-inch. 

2.  Of  these  the  Parrott  150-pounder  was  adopted  for  the  naval  ser- 
vice, but  was  subsequently  laid  aside  on  the  recommendation  of  a  board. 
The  proofs  to  which  each  has  been  subjected  will  be  found  in  the  replies 
to  previous  queries. 

The  mode  of  proceeding  in  proof  or  experiment  with  these  guns  has 
not  been  such,  owing  to  the  pressure  of  circumstances,  as  to  furnish  the 
means  of  replying  accurately  in  regard  to  the  endurance  of  these  rifled 
cannon. 

Some  of  the  guns  of  different  systems  have  exhibited  endurance  under 
fire  that  would  satisfy  any  requirement  of  naval  service;  and  others  of 
the  same  kind  have  proved  so  inferior  as  to  destroy  confidence. 

It  must  be  kept  in  view  that  a  uniform  endurance  with  service  charges 
is  the  chief  desideratum,  even  though  it  be  moderate.  This  cannot  be 
supplied  by  the  excessive  endurance  of  some  pieces  if  others  fall  very 
low. 

To  the  last  paragraph  of  this  interrogatory,  I  would  say,  that  this 
bureau  is  not  cognizant  of  any  rifled  cannon  of  heavy  calibre  whose 
admitted  character  would  warrant  its  being  adopted  for  the  ordnance  of 
our  navy. 

A  glance  at  the  accounts  from  abroad  do  not  show  that  in  this  respect 
we  are  worse  off  than  other  naval  powers. 

England  has  been  credited  more  than  once  with  being  on  the  eve  of 
solving  the  problem.  But  Armstrong  and  his  coadjutors  have  passed  off 
the  stage  to  make  place  for  others  who  in  the  end  may  prove  as  unlucky 
as  himself.  But  a  few  days  since  we  learnt  that  one  of  the  present 
favorite  guns  gave  way,  prematurely,  to  the  great  detriment  of  the  rep- 
utation of  its  class,  as  will  be  seen  by  the  following  extract  from  the 
Army  and  Navy  Journal  of  the  23d  of  January,  1869 : 

Our  London  military  contemporary  informs  us  that  the  admiralty  are  alarmed  at  the  explo- 
sion of  a  Fraser  gun  at  Woolwich.  It  says  they  have  been  in  communication  with  the  war 
office,  expressing  their  apprehensions  on  the  subject  of  the  large  forgings  in  vogue  at  the 
royal  gun  factories,  though  they  have  not  gone  as  far  as  to  repudiate  the  Fraser  gun  alto- 
gether. Indeed,  eight  10-inch  guns  have  just  been  put  on  board  the  Hercules. 
######* 

We  can  only  regret  (adds  the  Gazette)  that  the  idea  of  a  good  gun  seems  as  far  off  as  ever, 
meaning  by  a  '  good,"  one  which  can  be  relied  on  with  perfect  security. 

Of  course  we  will  some  day  have  a  rifle  cannon  equal  to  any  require- 
ment, but  much  time  may  elapse  and  more  money  will  be  spent  before 
that  will  happen. 

GUN-BLOCKS. 

At  the  commencement  of  the  year  1868,  a  reply  was  forwarded  to  a 
call  of  the  committee  for  information  in  regard  to  iron  castings  for  rifle 
cannon  that  were  to  be  finished  at  the  Washington  navy  yard,  which  will 
not  be  fully  understood  without  further  explanation,  and  I  therefore  ask 
permission  to  supply  this  now  very  briefly. 

The  whole  of  this  operation  is  to  be  considered  as  part  of  an  effort  by 
the  Bureau  of  Ordnance  to  meet  the  deficiencies  of  the  navy  in  rifle  can- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          145 

non,  under  circumstances  too  urgent  to  permit  of  the  least  delay.  It 
cannot  therefore  be  tried  by  any  of  the  ordinary  conditions  of  peaceable 
times. 

When  the  rebellion  broke  out,  in  April,  1861,  by  the  attack  on  Fort 
Sumter,  the  navy  was  the  least  prepared  to  exert  the  power  which  the 
extreme  need  of  the  country  demanded.  Among  other  deficiencies  it 
was  without  a  single  rifle  cannon  of  heavy  calibre. 

The  Bureau  of  Ordnance  had  for  several  years  previous  retarded  the 
investigation  of  this  question,  which  I  desired ;  and,  with  the  exception 
of  some  rifle  howitzers,  to  complete  the  boat  armament,  and  a  few  iron 
cannon  for  experiment,  we  had  no  rifle  pieces  for  the  naval  service. 

In  view  of  the  great  emergency,  it  became  the  imperative  duty  of  the 
Bureau  of  Ordnance  to  resort  to  every  expedient  that  held  out  the  least 
prospect  of  meeting  the  immediate  necessity,  and  reluctant  as  I  might 
be  to  venture  upon  results  with  the  scanty  data  at  hand,  particularly  as 
the  great  difficulty  of  the  problem  had  staggered  the  ablest  ordnance 
men  in  other  countries,  yet  I  felt  it  incumbent  on  me  to  spare  no  effort 
that  would  contribute  to  the  common  good,  even  if  in  so  doing  some 
damage  might  be  incurred  to  my  professional  reputation. 

All  the  foundries  and  workshops  of  the  north  were  being  filled  rapidly 
with  orders  for  the  building  of  steam  engines  and  the  fabrication  of  can- 
non for  the  army  and  navy ;  so  that  it  became  expedient  to  call  into 
action  the  mechanical  resources  of  the  navy  yard  here,  and  in  this  way 
the  castings  intended  for  rifled  cannon,  which  could  not  be  then  finished 
chiefly  at  the  Pittsburg  foundry,  were  brought  to  Washington  for  that 
purpose. 

It  is  not  to  be  supposed  that  there  was  the  same  leisure  for  careful 
scrutiny  when  the  rebel  flag  was  flaunted  in  sight  of  the  capital  that 
there  had  been  in  the  recent  periods  of  peace. 

The  founders  proceeded  to  make  the  castings  rapidly,  and  as  fast  as 
room  occurred  on  the  lathes  of  the  navy  yard,  these  were  put  under 
process. 

With  all  the  haste  that  could  be  used,  the  first  of  these  were  not  com- 
pleted until  the  latter  end  of  the  year  1861,  when  the  examination  of  the 
iron  and  the  test  of  firing  were  had. 

I  then  became  aware  that  the  tensile  strength  and  density  were  by  no 
means  satisfactory,  and  drew  the  attention  of  the  bureau  to  the  proba- 
bility of  accident  if  this  was  not  rectified.  A  little  later  I  was  led  to 
doubt  if  these  castings  were  of  cold-blast  iron,  and  I  recommended  the 
chief  of  bureau  to  withdraw  all  of  them  from  service  that  were  not  cold- 
blast,  and  to  receive  none  that  were  warm-blast. 

I  may  here  remark  that  some  difference  of  opinion  exists  in  regard  to 
the  necessity  of  cold-blast  iron  for  cannon.  It  would  consume  too  much 
of  the  time  of  the  committee  for  me  to  state  the  questions  in  detail,  but 
with  a  single  exception  I  believe  it  may  be  said  that  experienced  ord- 
nance officers  have  insisted  on  cold-blast  iron,  while  the  founders  con- 
sider warm-blast  good  enough.  It  is  certainly  easier  and  cheaper,  at 
first  cost,  to  make  iron  by  warm-blast  in  smelting. 

My  own  opinion,  derived  from  no  little  experience  in  iron,  always  has 
been  in  favor  of  cold-blast,  even  for  smooth-bores. 

As  the  examination  proceeded,  the  lack  in  quality  appeared  in  greater 
degree.  In  two  50-pounders  the  density  fell  as  low  as  7.121  and  7.160. 
In  stating  this  to  the  bureau  (26th  April,  1862,)  I  remarked: 

It  would  be  hazardous  to  send  into  service  guns  of  such  low  density.  All  the  difficulties 
which  have  been  experienced  with  the  80-pounders  and  150-pounders  are  entirely  owing  to 
this  and  to  other  disqualifying  causes,  and  I  have  already  asked  that  blocks  affording  a 
more  suitable  density  might  be  sent  here,  but  have  not  yet  been  furnished  with  them. 

Rep.  No.  266 10 


146  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

In  this  stage  of  the  matter,  the  House  of  Bepresentatives  asked  for 
information,  and  was  answered  by  myself  July  8,  1862;  and  by  Captain 
Harwood,  the  chief  of  bureau,  July  10,  1862. 

From  my  own  reply,  I  extract  the  following : 

The  fabrication  of  rifled  cannon  may  be  said  to  have  only  begun  in  this  yard  with  the 
present  struggle  for  the  Union. 

Little  or  nothing  more  was  done  between  this  and  the  period  when  Fort  Sumter  was 
attacked. 

Then  the  work  of  armament  really  began,  and  this  department,  so  limited  in  its  means, 
and  so  little  calculated  to  render  any  great  assistance  in  the  fabrication  of  cannon,  was  called 
upon  to  contribute  its  quota,  which  has,  I  believe,  been  faithfully  rendered. 

The  work  has  been  conducted  day  and  night,  even  while  the  flag  of  rebellion  was  flying 
within  sight,  not  omitting  Sunday,  for  which  I  did  not  escape  censure. 

To  this  the  bureau  added,  July  10,  1862 : 

The  investigations  on  the  subject  of  rifle  cannon  had  hardly  commenced  at  the  breaking 
out  of  the  rebellion,  &c.,  &c.  See  page  —  under  head  of  ("  Rifle  150-/Hwnrfer.") 

The  origin  of  the  whole  trouble  lay  entirely  in  the  postponement  of 
the  question  by  former  chiefs  of  bureau. 

In  1856  Captain  Ingraham,  then  chief  of  bureau,  would  take  no  action 
on  my  proposition  to  make  a  heavy  rifled  cannon,  nor  in  1857,  when  I 
renewed  it. 

In  1859  I  was  allowed  to  make  some  experiments  on  a  small  scale,  but 
even  this  was  arrested  in  January,  1860. 

Permission  to  continue  was  yielded  in  October,  1860,  when  rebellion 
stared  us  in  the  face.  But  it  was  too  late;  all  the  millions  since  spent 
by  the  country  would  not  buy  back  the  years  that  had  gone  by  unim- 
proved, and  we  went  into  the  conflict  like  a  man  picking  up  the  first 
weapon  at  hand. 

The  report  of  progress  which  I  made  in  December,  1860,  (already 
given,)  should  have  been  possible  four  years  previously,  w^hen  one  cast- 
ing after  another,  in  due  succession,  would  have  afforded  the  means  of 
correction  economically,  instead  of  the  wholesale  trials  of  1861,  when 
success  was  worth  any  cost,  and  which  cannot  therefore  be  tried  by  the 
standard  of  peaceable  times,  but  only  by  the  desperate  necessities  of  the 
Union  striving  for  existence.  In  view  of  which  it  became  not  the  Bureau 
of  Ordnance  nor  myself  to  hesitate  because  some  personal  sacrifice  was 
demanded. 

In  conclusion,  the  material  then  procured  is  by  no  means  useless,  even 
if  it  be  unfit  for  rifled  cannon ;  the  best  of  the  castings  may  be  made  into 
smooth-bores,  and  the  balance  used  for  other  purposes. 

CONCLUSION. 

The  queries  of  the  committee  were  received  by  me  on  the  25th  Decem- 
ber, and  it  was  my  desire  to  reply  to  them  in  the  fullest  manner;  the 
brief  period  that  remained  of  the  session  would  not  permit  me,  however, 
to  do  more  than  is  presented  in  the  foregoing. 

I  trust  it  will  have  the  consideration  of  the  committee  that  my  direct 
connection  with  the  Bureau  of  Ordnance  ceased  some  five  years  ago,  and 
was  only  resumed  a  few  months  since ;  that  I  was  absent  from  the  United 
States  during  the  greater  part  of  this  period,  in  command,  successively, 
of  two  of  our  squadrons.  My  knowledge,  therefore,  of  much  of  the  matter 
that  forms  the  subject  of  the  committee's  inquiry  was  unavoidably  to  be 
derived  or  renewed  from  a  scrutiny  of  the  records  of  this  office  accumu- 
lating since  1861,  amounting  (as  reported  to  me)  to  more  than  700  file- 
books  of  letters,  correspondence,  reports,  inspections,  &c. 

The  committee  may  conceive  that  it  was  impossible  for  me  to  do  this 
myself  or  to  have  it  done  with  entire  exactness  in  the  time  at  niy  dis- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  147 

posal.  I  hope,  however,  that  the  purposes  of  the  committee  may  be  suffi- 
ciently met  by  further  explanation  in  any  respect  that  the  committee 
may  indicate. 

With  the  permission  of  the  committee,  I  beg  leave  to  note  in  conclu- 
sion— 

1.  That  when  the  rebellion  began  in  1861,  the  experimental  investiga- 
tion of  the  rifled  cannon  problem  had  gone  no  further  than  the  rifled 
howitzer  for  boats,  (entirely  successful,)  and  some  of  lighter  iron  calibres — 
the  progress  having  been  delayed  previously  (1856  and  1857)  by  the 
decision  of  the  chief  of  the  bureau. 

2.  As  a  consequence  the  navy  was  destitute  of  any  system  of  heavy 
rifled  cannon  that  was  entitled  to  reliance  when  the  rebellion  broke  out, 
and  it  became  necessary  to  meet  the  incessant  and  general  demand  for 
these  guns  by  supplying  for  immediate  use  whatever  was  procurable  and 
offered  the  prospect  of  even  temporary  usefulness;  and  thus  it  was  that 
the  course  of  investigation  which  belonged  to  the  experimental  ground 
was  unavoidably  transferred  to  actual  service,  with  the  certainty  of 
increased  cost  and  at  the  risk  of  life;  there  was  no  help  for  it.    It  does 
not  appear  that  any  other  course  was  open  to  the  naval  bureau.    It  was 
well,  indeed,  that  under  such  trying  circumstances  the  navy  had  a  sure  reli- 
ance on  the  most  powerful  smooth-bores  then  ~known. 

The  results  are  before  the  committee;  unsatisfactory,  it  is  true,  but 
not  more  so  than  those  of  foreign  navies,  attained  in  peaceable  times, 
with  every  advantage  of  careful  and  costly  experiment. 

The  attention  of  the  committee  has  already  been  drawn  (reply  to  query 
12)  to  the  reported  failure  of  one  of  the  successors  of  the  Armstrong 
system,  which  had  swept  away  the  long  established  ordnance  of  Eng- 
land, and  was  in  its  turn  put  aside  as  unreliable.  This  later  favorite 
seemed  to  fulfil  the  promise  of  hopes  long  deferred,  and  now  comes  its 
probable  condemnation. 

An  armament  of  new  breech-loading,  heavy  rifled  cannon,  which  I 
recently  saw  on  board  one  of  the  latest  French  iron-clads,  has,  I  am  told 
by  a  naval  officer  just  returned  from  Europe,  lately  disappointed  expec- 
tation by  the  bursting  of  one  of  the  kind  in  a  ship  of  the  squadron  of 
evolution. 

We  have  now  the  opportunity  of  guarding  the  future  against  a  recur- 
rence of  the  losses  and  failures  experienced  in  the  late  struggle  by  resort- 
ing to  careful  experiment,  the  most  sure  of  success  at  the  least  cost. 

The  difficulty  of  the  question  has  been  much  ameliorated  by  the  changes 
of  views  which  have  occurred  in  regard  to  the  uses  of  rifled  cannon  since 
the  opening  of  the  rebellion. 

Then  all  opinion,  professional  or  public,  placed  no  dependence  on  cannon 
that  were  not  rifled;  the  utmost  anxiety  was  manifested  to  displace  the 
smooth-bores  and  substitute  rifled  cannon.  Had  it  been  possible  nothing 
else  would  have  appeared  in  our  ships,  so  extravagant  were  the  expec- 
tations that  prevailed  of  their  power. 

Yery  different  are  the  views  now  entertained.  The  experience  of  battle 
in  the  use  of  both  kinds  of  ordnance  has  restored  the  confidence  in  smooth- 
bores, not  only  for  their  certain  and  safe  endurance,  but  for  their  power 
and  their  accuracy  within  any  range  that  earnest  men  are  likely  to  try 
issues  on  the  ocean.  It  has  been  shown  that  the  true  role  of  rifled 
cannon  afloat  is  very  limited,  and  that  its  numbers  on  shipboard  will 
therefore  be  proportionally  few. 

I  can  offer  no  bette  revidence  in  this  respect  than  the  views  of  Vice- 


148          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Admiral  Porter,  whose  great  experience  in  severe  action  will  not  fail  to 
receive  due  weight.    He  says  : 

The  gun  which  I  deem  best  adapted  to  the  general  use  in  the  navy  is  the  11 -inch  gun, 
which  can  be  carried  on  board  even  our  smallest  vessels,  worked  in  a  sea-way  if  the  vessels 
are  properly  constructed,  and  almost  as  rapidly  as  a  32-pounder ;  at  all  events  rapidly  enough 
for  all  practical  purposes. 

I  consider  its  accuracy  much  greater  than  any  rifle  gun  or  any  gun  of  a  smaller  calibre. 
That,  I  believe,  has  been  tested  to  the  satisfaction  of  most  navy  officers.  1  am  no  advocate 
for  a  large  number  of  heavy  rifled  guns  on  board  ship,  although  I  think  it  does  very  well  to 
have  a  few  combined  with  smooth-bores.  I  have  no  confidence  in  their  accuracy  at  sea  ;  on 
shore,  where  they  are  mounted  on  a  good  level  platform,  and  where  allowances  can  be  made 
for  wind  and  weather,  they  will  do  very  well,  but  on  shipboard,  where  there  is  the  least 
motion,  they  fire  very  inaccurately. 

If  they  should  strike  the  w?.ter  before  reaching  the  object  they  are  deflected  at  an  angle  of 
45°  and  go  wide  of  the  mark. 

That  most  important  power,  "  ricochet  firing,"  is  entirely  lost  in  the  rifle  guns,  and  in  a 
sea-way  a  vessel  armed  with  ]  1-inch  guns  is,  in  my  opinion,  a  match  for  a  vessel  with  twice 
the  number  of  rifle  guns. 

I  am  not  prejudiced  against  rifle  guns  from  the  fact  that  I  have  had  a  good  many  of  them 
burst,  as  I  believe  that  most  of  those  that  burst  were  badly  constructed,  which  I  think  is  the 
case  with  all  banded  guns. 

I  regret  to  say  that  I  have  seen  many  men  killed  and  wounded  by  the  bursting  of  100- 
pounder  rifles,  and  many  vessels  injured. 

The  result  of  these  accidents  has  been  to  impair  the  confidence  of  sailors  in  that  class  of 
guns,  and  were  I  going  to  sea  I  would  not  have  one  on  board. 

I  have  never,  to  my  knowledge,  known  an  accident  happen  to  the  9,  10,  or  11-inch  guns, 
three  of  the  best  guns  we  have  ever  had  in  our  navy ;  and  in  battle  men  stand  behind  these 
guns  in  perfect  security,  knowing  that  the  chance  of  their  bursting  is  very  small. 

I  do  not  want  you  to  suppose  that  I  am  an  advocate  for  the  abolition  of  rifle  guns,  for  I 
believe  that  excellent  cannon  of  that  kind  can  be  made  of  cast-iron  without  banding. 

What  we  need  is  a  course  of  well-conducted  experiment,  carefully, 
logically  pursued  by  officers  whose  experience  renders  them  cognizant  of 
all  views  of  the  question. 

My  report  of  1862,  as  chief  of  bureau,  shows  that  I  then  attained 
results  which  should  have  led  the  way  to  further  experiment  and  per- 
haps to  useful  conclusions.  It  is  to  be  regretted  that  these  were  not 
pursued  to  that  end. 

The  ample  building  at  the  navy  yard,  where  I  had  hoped  to  examine 
fully  into  the  quality  of  different  American  iron,  the  modes  of  treatment 
likely  to  insure  the  best  metal,  and  to  test  the  various  models,  has  been 
converted  into  a  receptacle  for  unused  and  obsolete  ordnance  stores  of 
all  kinds. 

I  feel  that  the  committee  can  restore  the  operations  of  this  bureau  to 
their  true  course,  by  recommending  some  moderate  sum  for  experimental 
purposes,  and  by  separating  the  practical  ordnance  duties  from  the 
merely  administrative ;  which  is  the  more  needed  in  the  navy  because 
we  have  no  distinct  ordnance  corps  like  the  army,  but  trust  to  details  of 
officers  from  the  line  of  service  for  carrying  on  every  branch  of  naval 
ordnance  duty,  from  the  inspection  of  cannon  to  fitting  of  ships  at  the 
navy.  yard. 

For  the  convenient  reference  of  the  committee  I  annex  a  list  of  the 
most  recent  chiefs  of  Ordnance  Bureau :  Captain  Ingraham,  March  10, 
1856,  to  September,  23,  1860 ;  Captain  Magruder,  September  24,  1860, 
to  April  23,  1861 ;  Captain  Harwood,  April  24,  1861,  to  July  22,  1862  ; 
Captain  Dahlgren,  July  22,  1862,  to  June  24,  1863 ;  Captain  Wise,  June 
27,  1863,  to  June  1,  1868;  Rear- Admiral  Dahlgren,  July  22,  1868,  to  the 
present  date. 

I  have  the  honor  to  be,  very  respectfully,  your  obedient  servant, 

J.  S.  DAHLGKEN, 
Rear-Admiral  and  Chief 'of  Bureau. 

FEBRUARY  11, 1869. 


EXPERIMENTS   ON   HEAVY    ORDNANCE.  149 

APPENDIX  C. 

OFFICIAL  REPORTS. 

From  the  report  of  the  Chief  of  Ordnance,  Wavy  Department,  for  1861. 

With  reference  to  rifled  cannon,  for  which  there  has  been  an  unceasing 
demand,  the  bureau,  after  mature  consideration,  decided  that  it  would 
be  injudicious  to  rifle  the  old  navy  models,  on  account  of  their  form  not 
being  adapted  to  the  severe  strain  to  which  rifled  ordnance  is  subjected. 
Another  consideration  which  added  force  to  this  decision  was,  that  in 
the  guns  formerly  made  for  the  navy  the  treatment  of  the  iron  was  dif- 
ferent from  that  pursued  in  more  recent  years,  and  which  is  now  deemed 
to  be  a  matter  of  paramount  importance. 

But  to  meet  as  near  as  was  practicable  pressing  emergencies,  the 
bureau,  after  due  investigation  into  the  best  description  of  this  kind  of 
ordnance,  selected  that  which  was  available,  and  which  has  been  pro- 
duced by  the  enterprise  of  private  establishments. 

Meanwhile  the  genius  of  Commander  Dahlgren  designed  new  models 
for  rifled  cannon,  which  have  been  put  in  hand ;  and  now,  with  every 
possible  appliance  of  foundries  and  machine  shops  that  are  found  avail- 
able throughout  the  country,  as  well  in  the  public  works  as  in  private 
establishments,  there  is  every  reason  to  believe  that,  under  any  probable 
contingency  which  may  arise,  the  demand  for  ordnance  will  be  promptly 
supplied  with  cannon  fully  equal,  if  not  superior,  to  any  known  to  exist 
at  home  or  abroad. 

From  the  report  of  the  Chief  of  Ordnance,  Navy  Department,  for  1862. 

The  constant  and  very  natural  solicitude  manifested  by  the  public  in 
the  changes  which  have  been  and  continue  to  be  made  in  the  construc- 
tion and  armament  of  our  ships-of-war  may  warrant  a  more  extended 
notice  of  technical  detail  than  might  otherwise  find  place  in  a  document 
of  this  nature. 

And  yet  no  definite  conclusion  has  been  reached  in  regard  to  either  of 
these  important  problems. 

Indeed,  the  most  casual  observer  of  current  events  can  hardly  fail  to 

perceive  that  neither  of  them  has  advanced  beyond  the  first  proposition. 

*  #  *  *  *  *  * 

The  advantage  of  which  is  now  apparent  from  the  fact  that  our  9- 
inch  and  11-inch  guns  are  found  to  be,  in  a  measure,  available  against 
iron-plating,  because  they  will  endure  solid  shot  fired  with  one-half 
greater,. and  even  double,  the  original  charges. 

So  that  we  have  the  leisure  to  consider  and  devise  any  other  species 
of  ordnance  that  may  be  better  adapted  to  the  purpose,  and  are  not  pre- 
cipitated into  hasty  or  questionable  measures. 

******* 

The  ordnance  expert  can  by  no  means  rejoice  in  being  free  from  diffi- 
culties that  puzzle  his  ingenuity. 

The  number  of  cannon  being  reduced  to  a  third  of  the  number  he  is 
accustomed  to  rely  upon,  how  shall  he  supply  the  loss  of  force  by  the 
weight  and  kind  of  those  which  remain  I 

If  he  acquires  power  by  greater  weight,  he  loses  by  loss  of  time  in 
manipulation  of  gun  and  projectile ;  hence  some  reduction  by  slowness  of 
repetition.  Then,  again,  shall  he  use  our  smooth-bore,  breech  or  muzzle- 
loaders?  Shall  he  pierce  or  crush  and  break  bolts  and  strip  off  the 
armor,  or  shall  he  even  attempt  to  enter  the  interior  with  shells  ? 


150  EXPERIMENTS   ON   HEAVY    ORDNANCE. 

How  economize  the  open  space  of  the  ports  when  the  gun  is  out,  or 
close  it  when  in  ? 

Leaving  these  queries  to  be  answered  by  the  parties  most  concerned, 
it  will  suffice  here  to  say  that,  just  now,  the  offence  has  decidedly  the 
advantage,  and  no  sea- going  ship  is  considered  to  be  so  armored  as  to 
be  impregnable  to  artillery.  Of  the  French  results  and  inferences  touch- 
ing the  several  points  we  know  nothing  beyond  what  is  necessarily  dis- 
closed to  the  observer  in  the  construction  of  ships. 

The  British  government  have  practiced  less  reticence  ;  and  if  we  are 
not  permitted  to  become  acquainted  with  the  reasoning  of  their  officials, 
the  results  from  which  they  do  reason  are  so  far  public  that  one  cannot 
err  very  widely  as  to  their  general  bearing. 

A  large  number  of  witnesses  have  usually  been  present  at  the  trials, 
including  officers,  engineers,  ship-builders,  and  others,  civil  and  official. 
The  press  is  also  well  represented,  and  in  a  few  days  afterwards  all  the 
proceedings  are  detailed  minutely  to  the  public,  discussed  in  Parliament, 
and  in  meetings  where  the  ablest  professional  men  are  assembled  for 
the  purpose. 

So  far  as  an  opinion  can  be  formed  from  such  sources,  one  is  led  to 
conclude  that  those  who,  from  their  distinguished  abilities  and  oppor- 
tunities of  investigation,  should  be  best  qualified  to  judge,  have  arrived 
at  no  final  decision  in  regard  to  any  of  the  essential  points  of  the  prob- 
lem above  stated,  which  is,  indeed,  reasonable,  when  it  is  noticed  to 
what  extent  these  differ  and  even  conflict. 

About  a  year  since  (October  21,  1861)  a  number  of  eminent  dignita- 
ries, military,  naval,  and  civil,  met,  in  order  to  witness  the  trial  of  a 
target  representing  the  Warrior's  sides.  It  was  supposed  that  all  the 
power  which  ordnance  could  exert  for  such  a  purpose  was  brought  into 
play ;  and  after  this  had  been  done  it  seemed  as  if  the  witnesses  were 
generally  favorably  impressed  with  the  endurance  of  the  target,  and 
therefore  of  the  Warrior. 

But  not  long  after  (April  8, 1862)  Sir  William  Armstrong  placed  in 
front  of  this,  or  a  similar  target,  a  gun  which  he  had  just  completed  ;  it 
threw  a  round  shot  of  156  pounds,  which,  with  50  pounds  of  powder, 
most  unexpectedly  changed  the  whole  aspect  of  the  question  by  its  treat- 
ment of  the  target,  which  was  said  to  have  been  completely  pierced. 

The  revulsion  in  common  opinion  went  so  far  as  to  discredit  the 
Warrior  entirely,  and  the  fallibility  of  that  vessel  was  pronounced  certain. 

But  during  a  discussion  in  Parliament  a  member  maintained  that  the 
facts  had  not  been  accurately  stated  even  by  official  authority,  and  the 
deductions  were  consequently  more  unfavorable  to  the  target  than  was 
correct.  He  even  affirmed  that  the  target  had  not  been  fatally  injured, 
but  would  in  fact  have  kept  out  the  shot  from  entering  a  vessel. 

Whether  for  this  reason  or  not,  the  trial  was  repeated,  and  very  fully 
disposed  of  all  doubts  in  favor  of  the  target  j  but  it  settled  the  gun  also, 
which  burst  at  the  fourth  round. 

Thus  demonstrating  that  if  the  target  were  penetrable  by  the  fire  of 
such  a  piece  of  ordnance,  it  was  only  by  an  effort  that  destroyed  the 
gun  also — a  risk  not  to  be  thought  of  on  shipboard. 

And  hence  it  was  inferred  that  the  Warrior  was  impregnable  to  the 
effort  of  any  ordnance  that  could  be  then  used  safely  against  her. 

The  triumph  of  the  defence  was,  however,  of  short  duration ;  for  the 
rupture  of  the  Armstrong  gun  left  the  way  open  to  other  competitors, 
and  a  long-neglected  piece  that  had  lain  remote  from  view  for  several 
years  was  suggested  as  deserving  of  an  opportunity  to  try  its  powers. 

This  was  the  Horsfall  13-inch,  of  wrought  iron.    Its  first  blow,  with  a 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          151 

shot  of  280  pounds,  was  decisive.  The  plate  was  pierced  and  badly 
injured,  while  the  endurance  of  the  gun  was  untouched. 

As  if  to  complete  the  entire  failure  of  the  defence,  and  to  puzzle  its 
advocates,  Mr.  Whitworth  undertook  to  drive  a  shell  through  a  stout 
iron-plated  target,  which  he  accomplished. 

So  that  the  system  of  armor  that  had  been  relied  on  was  proven  to  be 
vulnerable  by  shells,  as  well  as  by  shot,  which  was  an  unhoped-for  advan- 
tage on  the  side  of  the  attack. 

Here  it  will  probably  rest  for  the  while,  until  the  defence  shall  be  able 
to  devise  some  plan  of  greater  efficacy. 

It  would  be  unwise,  however,  to  rush  to  the  conclusion  that  armor  is 
needless,  because  the  most  powerful  ordnance  should,  under  skilful 
guidance,  be  able  to  pierce  it. 

For,  even  against  such  cannon,  a  ship  may  delay  the  final  disaster 
long  enough  to  make  its  own  guns  of  avail  ;  and  when  opposed  to  any 
but  these  heaviest  pieces,  will  still  be  in  effect  impregnable. 

The  case  of  the  Monitor  and  Merrimack  affords  an  illustration. 

No  one  supposes  that  either  of  these  vessels  could  have  escaped  serious 
injury  if  subjected  to  a  course  of  target-firing  from  the  most  recent  and 
powerful  descriptions  of  ordnance,  yet  they  sustained  for  four  hours  the 
utmost  effort  of  each  other's  batteries. 

The  Monitor  was  hardly  more  than  scarred  by  the  fire  of  the  very 
guns  Avhich,  on  the  preceding  day,  had  in  a  fourth  of  the  time  acted  most 
destructively  on  the  hulls  and  crews  of  two  fine  wooden  frigates. 

A  very  high  official  authority  (Duke  of  Somerset,  First  Lord  of  the 
Admiralty,  House  of  Lords,  April  3,  1862)  has,  to  be  sure,  imputed  the 
default  of  injury  to  life  or  limb  in  this  combat  to  a  lack  of  power  in  the 
artillery  which  the  two  vessels  carried ;  which  is  no  doubt  true  ;  but  it 
is  equally  true  that  no  guns  of  like  weight  and  kind  now  used  in  the 

British  navy  would  have  effected  as  much  under  like  circumstances. 

*  ***** 

The  operations  that  have  been  conducted  here  with  reference  to  the 
power  of  different  cannon  and  projectiles,  as  well  as  the  resistance  of 
iron  plating,  have  been  so  far  satisfactory  that  the  results  derived  have 

been  consistent. 

******* 

There  must  be,  however,  a  material  reduction  in  the  celerity  of  fire 
with  guns  and  projectiles  so  large  as  the  15-inch,  whatever  may  be  the 
mechanical  appliances  which  may  be  brought  to  assist. 

An  11-inch  gun,  with  a  well-disciplined  crew,  can  be  fired  once  a 
minute  ;  but  there  must  be  much  improvement  in  any  mode  now  sug- 
gested before  a  15-inch  gun  can  be  fired  once  in  thrice  that  time. 

As  a  certain  capacity  for  repetition  is  essential  to  the  general  power 
of  a  battery,  there  is  thus  involved  a  disadvantage  which  can  only  be 
compensated  to  any  extent  by  the  great  concentration  of  effect  in  the 
individual  projectiles.  For  it  may  be  conceived  that  the  effects  of  shells 
of  330  pounds,  and  shot  of  450  pounds,  will  be  damaging  beyond  any 
experience  in  former  battles.  What  may  be  the  power  of  such  ordnance 
against  iron-cased  ships — comparative  or  absolute — remains  to  be  ascer- 
tained. This,  as  well  as  the  piece  itself,  is  yet  but  an  experiment. 
****** 

On  another  occasion  an  11-inch  gun  was  fired  500  times,  of  which 
170  fires  per  day  were  made  in  two  successive  days,  which  so  heated 
the  gun  that  it  was  found  to  be  warm  18  hours  afterwards.  No  sign 
of  weakness  was  detected. 


152          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

From  the  report  of  the  Chief  of  Ordnance,  N~avy  Department,  for  1863. 

The  only  establishments  in  the  country  which  were  prepared  for  the 
work  of  founding  heavy  cannon,  when  the  rebellion  took  place,  were  the 
South  Boston,  Fort  Pitt,  and  West  Point;  the  Tredegar  Works  at  Eich- 
mond,  Virginia,  having  passed  into  the  hands  of  the  rebels.  No  govern- 
ment establishment  of  the  kind  existed,  and  consequently  the  sole  reli- 
ance of  both  army  and  navy,  at  the  commencement  of  our  difficulties, 
was  upon  these  three  foundries. 

Eight  nobly,  however,  did  they  come  to  the  rescue  in  the  hour  of  need, 
and  thus  afforded  time  for  the  bureau  to  seek  other  manufacturers 
who  might  be  willing  to  undertake  the  work  of  supplying  the  navy  with 
cannon. 

Although  such  operations  are  always  attended  with  great  risk  to  those 
who  were  unaccustomed  to  the  casting  of  heavy  guns,  it  was  not  long 
before  several  other  establishments  were  ready  to  co-operate,  and  the 
work  of  producing  the  guns  of  various  calibres  required  was  commenced, 

and,  I  am  happy  to  say,  been  most  successfully  prosecuted. 

****** 

In  procuring  cannon  for  the  navy  the  same  conditions  have  been 
exacted  from  all  these  foundries,  as  regards  the  character  of  metal  and 
every  other  element  necessary  to  constitute  good  and  reliable  guns. 
No  gun  has  been  accepted,  as  a  standard,  which  has  not  been  subjected 
to  the  ordeal  of  1,000  rounds  of  service  charges.  With  this  standard 
thus  established,  all  the  guns  of  a  contract  must  coincide  in  their  com- 
posite elements. 

The  only  exception  to  this  rule  has  been  in  the  case  of  the  15-inch 
guns  cast  upon  the  plan  of  Major  Eodman,  of  the  United  States  army. 
Time  did  not  permit  of  this  proof  being  applied,  and  the  guns  were 
necessarily  accepted  and  put  into  service,  after  having  endured,  how- 
ever, somewhat  more  than  the  tests  prescribed  by  the  army  regulations. 

It  is  most  gratifying  to  know  that  the  judgment  of  the  Navy  Depart- 
ment has  been  sustained  by  the  result  of  the  further  test  which  has  been 
applied  to  the  first  gun  of  this  class  made  for  the  navy,  and  which  is  still 
undergoing  a  series  of  experimental  firing  after  being  modified  in  form. 
All  doubt  is  thus  removed  of  the  ability  of  the  Fort  Pitt  foundry  to  pro- 
duce guns  of  this  great  size  which  can  safely  be  relied  upon ;  and  the 
power  thereby  added  to  the  fire  of  our  monitors  has  been  most  fully 
exemplified  in  the  capture  of  the  Atlanta. 

Before  dismissing  this  branch  of  its  report,  it  is  just  that  the  bureau 
should  bear  special  testimony  to  the  prompt  and  efficient  manner  in 
which  the  West  Point  foundry  has  also  done  its  share  in  supplying  the 
need  of  the  service  for  a  new  style  of  ordnance. 

The  introduction  of  a  few  rifled  guns  of  heavy  calibre  into  the  bat- 
teries of  ships  had  already  taken  place  in  foreign  navies  prior  to  the 
date  of  our  present  rebellion  ;  and  in  our  own  service  experiments  were 
being  conducted  at  the  Washington  navy  yard,  under  the  direction  of 
Eear- Admiral  Dahlgren,  for  the  purpose  of  devising  a  system  of  rifled 
ordnance.  Nothing  decisive,  however,  has  been  accomplished,  except 
with  the  rifled  howitzer,  and  the  experiments  were  rudely  interrupted 
in  the  spring  of  1861. 

At  the  same  time  Mr.  Parrott  was  engaged  in  perfecting  his  present 
system,  and  the  results  obtained  by  him  were  so  satisfactory  that  in  the 
summer  of  1862  the  bureau,  in  conjunction  with  the  army  ordnance, 
directed  a  100-pounder  to  be  subjected  to  a  series  of  1,000  service  rounds. 

The  gun  stood  the  test  without  bursting,  and  its  accuracy  and  range 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  153 

were  considered  sufficiently  good  to  warrant  the  adoption  of  these  rifled 
guns  as  a  permanent  part  of  our  naval  armament.  Since  then  the  demand 
for  the  several  calibres  has  been  unceasing ;  and,  as  before  stated,  they 
are  to  be  found  on  board  nearly  every  vessel  now  in  service,  and  will 
continue  to  be  supplied  until  some  better  system  is  established. 

Finally,  from  personal  inspection,  and  witnessing  the  firing  of  over  100 
rounds  from  these  guns  at  the  West  Point  foundry  recently,  the  bureau 
is  satisfied  that  whenever  attention  is  paid  to  details  and  even  moderate 
skill  in  the  manner  of  loading  and  firing  is  attained,  they  will  prove  the 
most  serviceable  rifled  guns  that  have  ever  been  introduced  into  any 
service. 

From  the  report  of  the  Chief  of  Ordnance,  War  Department,  for  1864. 

The  heavy  gun  of  20-inch  calibre,  for  sea-coast  fortifications,  has  been 
successfully  cast  and  finished,  and  a  suitable  carriage  to  mount  it  has 
been  prepared.  It  is  now  ready  for  experimental  trials  at  Fort  Hamil- 
ton, in  New  York  harbor,  and  the  proper  targets  and  other  preparations 
for  testing  its  efficiency  against  the  strongest  war  vessels,  and  ascertain- 
ing the  best  manner  of  handling  it  in  service,  have  been  ordered  to  be 
made.  The  results  of  these  trials  will  demonstrate  whether  the  expecta- 
tions which  theory  warrants,  of  the  destructive  effects  of  this  gun  and 
its  value  for  defensive  works  covering  narrow  passes,  are  realized,  and 
whether  such  guns  should  be  multiplied ;  and  if  so,  to  what  extent.  If 
they  should  establish  the  affirmative  of  this  question,  the  cost  of  these 
trials  will  be  far  outweighed  by  the  advantages  obtained  from  them ; 
if  otherwise,  the  loss  will  be  insignificant  in  itself,  and  will  probably  be 
a  gain  eventually,  by  preventing  future  experiments  in  the  same  line, 
and  settling  the  question  of  the  largest  effective  calibre  for  sea-coast 
cannon. 

From  the  report  of  the  Chief  of  Ordnance  of  the  Navy  Department  for  1864. 

COMPOSITION  OF  BATTERIES. 

The  governing  rule  in  arming  our  ships  of  war  has  been  to  place  on 
board  of  them  the  very  heaviest  and  most  effective  gun  they  can  bear 
with  safety. 

In  general  it  may  be  stated,  that  the  9-inch  are  used  for  broadside; 
the  10-inch,  11-inch,  and  the  Parrott  rifles  in  pivot ;  the  15-inch  for  the  mon- 
itor turrets,  and  the  bronze  howitzers  and  rifles  for  boat  and  deck  service 
in  shore.  A  few  of  our  ships  continue  to  be  armed  with  the  32-pounder 
and  8-inch  guns  of  the  old  system  5  but  these  will  probably  give  way  to 
the  modified  guns  of  similar  classes  above  alluded  to. 

As  no  special  changes  have  been  made  in  the  general  arrangement  of 
batteries  since  my  last  report,  the  same  vessels,  mentioned  therein  as 
types  of  their  rates,  may  be  again  taken  to  illustrate  the  system  of  arma- 
ment still  in  vogue. 

Thus  the  battery  of  a  first-rate  is  represented  by  the  Minnesota 
carrying — 

One  150-pounder  rifled,  )  .       .     , . 

One  11-inch  smooth,       }  m  plvot> 

Forty-two  9-inch  smooth,   )  .     broadside 

Four  100-pounders,  rifled,  }  u  le> 

and  four  howitzers. 


154  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

Of  a  second-rate  by  the  Brooklyn,  carrying — 
Two  100-pounder  rifled,  in  pivot; 
Twenty  9-ineh  smooth,    )  .     ,     „/••!« 
Two  60-pounder  rifledj    } ln  broadside' 
and  two  howitzers. 

Of  a  third-rate  by  the  Eutaw,  carrying — 
Two  100-pounder  rifled,  in  pivot ; 
Four  9-iuch  smooth,  } 

Two  24-pounders,  smooth,    >  in  broadside. 
Two  20-pounders,  rifled,       ) 

Of  the  fourth-rate  by  the  Owasco,  carrying — 

One  11-inch  smooth,    )  .      .     , 

One  20-pounder  rifled,  f  u 

Two  24-pounders,  howitzers,  in  broadside. 
And  by  the  Nipsic,  carrying — 

One  150-pounder  rifle,  )  . 

One  30-pounder  rifle,    }  m  pivot  5 

Two  9-inch  smooth,  in  broadside,  and  four  howitzers. 

Of  the  monitors,  by 

The  Tonawanda,  four  15-inch; 
The  Onondaga,  two  15-inch  and  two  150-pounders ; 
And  Montauk,  one  15-inch  and  one  1 50-pounder. 
Of  the  iron-plated  gunboat  of  the  western  rivers,  by  the  Carondelet, 
carrying  three  9-inch,  four  8-inch,  two  100-pounder  rifles,  one  50-pounder 
rifle,  one  30-pounder  rifle. 

The  development  of  the  power  of  each  individual  ship  named  as  repre- 
sentatives of  the  several  rates  is — 

In  shot.  In  shells. 

First  rate 2,606  Ibs.  2,123  Ibs. 

Second  rate 1,220  990 

Third  rate 424  343 

Fourth  rate 210  183 

And 294  255 

In  the  monitors — 

Tonawanda 1,704  1,320 

Onondaga 1,180  930 

Montauk 606  465 

In  the  western  gunboat — 

Carondelet 588     -  480 

It  will  be  noticed  that  in  each  of  the  four  rates  of  vessels  above  men- 
tioned pivot  guns  are  associated  with  those  of  broadside,  so  as  to  meet 
more  fully  the  necessity  for  long  range  at  high  elevations  in  chasing  or 
bombardment,  and  at  the  same  time  to  maintain  a  direct  fire  without 
materially  altering  the  course  of  the  vessel.  The  mechanical  arrange- 
ment of  the  pivot  carriage  also  enables  the  mounting  and  working  with 
ease  a  much  heavier  gun  than  could  possibly  be  handled  on  an  ordinary 
broadside  carriage. 

These  pivot  guns  are  always  placed  near  the  ends  of  the  vessel,  and 
therefore  do  not  interfere  in  the  least  with  the  working  of  the  broadside. 
The  rapidity  of  fire  from  them  is,  of  course,  not  so  great  as  from  an  indi- 
vidual gun  of  broadside,  but  is  fully  sufficient  for  the  purpose  of  accuracy 
at  ranges  beyond  the  reach  of  the  lesser  calibres.  No  ship  can,  there- 
fore, be  considered  properly  armed  that  has  not  a  pivot  gun  of  greater 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          155 

power  and  range  than  the  guns  of  broadside.  But  whether  a  battery, 
consisting  entirely  of  heavy  pivot  guns,  would  be  more  formidable  than 
one  of  broadside  alone — the  aggregate  weights  being  equal — has  not  yet 
been  tried,  the  only  effort  of  the  kind  being  that  of  the  Niagara,  which 
has  a  battery  of  twelve  150-pounder  rifles  mounted  in  pivot,  and  no  regu- 
lar broadside  guns. 

THE  FOUNDRIES. 

The  number  of  these  establishments  engaged  in  the  fabrication  of  can- 
non for  the  navy  has  been  reduced  by  one  since  the  date  of  my  last  report, 
the  Portland  Company  having  withdrawn  from  their  contract.  The 
others  have  been  fully  employed  in  the  work  of  keeping  the  navy  sup- 
plied with  guns  of  unequalled  strength  and  beauty  of  finish,  from  the 
ponderous  15-inch  to  the  light  32-pounder.  No  delay  or  embarrassment 
has  occurred  in  the  delivery  of  the  cannon  contracted  for,  and  the  bureau 
is  more  than  ever  assured  of  the  reliability  of  the  firms  engaged  in  this 
important  business. 

The  Fort  Pitt  foundry,  with  its  immense  facilities  and  very  great  expe- 
rience in  the  art  of  founding  cannon,  was  at  first  the  only  establishment 
able  and  willing  to  undertake  the  task  of  making  the  15-inch  guns.  But 
during  the  past  year  two  other  foundries — the  South  Boston  and  the 
Scott  foundries,  at  Beading,  Pennsylvania,  having  completed  all  the 
arrangements  necessary  for  the  process  of  hollow  casting — have  now 
each  a  contract  for  this  class  of  gun.  No  difficulty  whatever  is  antici- 
pated in  the  fabrication  of  these  very  large  cannon,  for  the  irons  now 
used  by  the  respective  foundries  are  known  to  be  of  the  very  best  quality 
for  the  purpose.  The  primary  and  most  important  element  being  thus 
assured,  the  remainder  of  the  task  is  entirely  within  the  mechanical 
ability  of  the  foundries. 

It  is,  therefore,  no  idle  boast,  that  the  cannon  of  the  United  States 
navy,  made  exclusively  from  American  irons,  are  unsurpassed  by  those 
of  any  other  nation ;  and  this  will  continue  to  be  the  case  so  long  as  the 
enterprise  of  our  citizens  is  left  untrammelled,  and  full  opportunities  are 
afforded  for  the  exercise  of  their  skill  in  this  most  important  art. 

Besides  the  15-inch  guns,  the  Fort  Pitt,  South  Boston,  and  Reading 
foundries  are  all  engaged  in  making  the  other  classes  in  use,  including 
also  the  new  models  of  8-inch  and  32-pounders  elsewhere  alluded  to.  The 
Builders'  Iron  Foundry,  at  Providence,  Ehode  Island,  has  just  completed 
a  contract  for  11-inch  guns,  and  is  now  engaged  on  a  new  one  for  the 
8-inch  and  32-pounders;  while  the  firm  of  Hinkley,  Williams  &  Co.  are 
still  engaged  upon  their  contract  for  11-inch  guns.  Thus  the  work  has 
been  steadily  prosecuted  during  the  past  year,  and  will  be  continued  by 
these  foundries  as  fast  as  the  demand  for  the  smooth-bores  increases. 

The  cast-iron  banded  rifles  of  Mr.  Parrott,  made  at  the  West  Point 
foundry,  are  still  the  only  kind  used  in  the  navy,  except  the  bronze  12 
and  20-pounders  of  Bear- Admiral  Dahlgren.  Since  November  of  last 
year  there  have  been  added  to  the  stock  of  these  rifles  on  hand  at  the 
depots  and  in  service  385  of  the  different  calibres,  including  20  new  60- 
pounders,  making  a  total  at  present  available  of  1,005  guns,  after  deduct- 
ing 23  lost  or  disabled  by  the  accidents  of  battle.  Of  these  thus  lost  or 
disabled,  six  gave  way  at  the  breech,  four  were  broken  by  the  explosion 
of  shells  near  the  muzzle,  three  were  cracked  in  the  bodies,  two  were 
condemned  for  excessive  enlargement  of  vent,  seven  were  lost  by  wreck, 
and  three  captured  by  the  rebels.  The  percentage  of  loss  by  rupture  and 
enlargement  is  therefore  very  small. 

It  may  be  remarked  that  no  rifled  gun  has  yet  been  devised  which  can 


156          EXPERIMENTS  ON  HEAVY  OEDNANCE. 

be  considered  perfect,  and  the  bureau  has  sought  in  vain  among  the  sys- 
tems of  European  nations  and  the  improvements  of  our  own  country  for 
a  better  gun,  taken  as  a  whole,  than  the  Parrott  rifle.  Its  lifetime,  as 
fixed  by  the  inventor,  is  750  rounds,  but  the  navy  guns  have  in  many 
instances  shown  a  greater  endurance. 

It  is  true  that  reports  are  occasionally  received  of  failures  with  the 
Parrott  projectiles,  (also  prepared  at  the  West  Point  foundry,)  but  these 
are  again  counterbalanced  by  the  most  favorable  reports ;  and  it  is  cer- 
tain that,  whenever  a  close  attention  is  paid  to  details  in  loading  and 
firing,  these  guns  may  be  relied  upon  for  range  and  accuracy.  But  if 
these  details  from  any  cause  are  not  sufficiently  attended  to,  the  firing 
of  no  rifled  gun  can  be  considered  safe  or  certain.  At  all  events,  what- 
ever may  be  the  defects  of  the  Parrott  system  of  rifled  ordnance,  no  other 
has  yet  been  produced  which  commends  itself  so  strongly  to  the  service ; 
and  until  another  and  a  better  one  is  devised  and  subjected  to  the  same 
ordeal,  the  bureau  will  continue  to  place  its  guns  in  the  batteries  of  ships 
as  important  auxiliaries  to  the  smooth-bore  pivots. 

The  condition  of  endurance  is  undoubtedly  the  first  to  be  secured  in 
all  guns,  and  no  one  expects  to  find  this  in  as  great  a  degree  in  the  rifle 
as  in  the  smooth-bore.  Hence  the  cast-iron  gun  of  Mr.  Parrott,  although 
strengthened  by  a  spiral  coil  of  wrought-iron  around  the  locality  of  great- 
est strain,  is  by  no  means  to  be  expected  to  last  as  long  under  protracted 
firing  as  a  smooth-bore  of  the  same  calibre.  But  its  probable  strength 
when  carefully  used,  as  all  ordnance  should  be,  is  sufficiently  ascertained 
to  avoid  accidental  rupture  by  attempting  too  much. 

Propositions  have  been  made  to  supersede  cast-iron  for  rifles  (and  in 
fact  for  smooth-bores  also)  by  wrought-iron ;  and  a  heavy  wrought-irou 
rifled  gun  of  7-inch  bore,  forged  in  a  peculiar  manner,  is  even  now  under 
process  of  trial,  as  well  as  one  of  smooth-bore,  designed  and  constructed 
by  our  distinguished  citizen,  Mr.  John  Ericsson.  But  the  experiments 
have  not  been  sufficiently  advanced  with  either  of  these  guns  to  form  a 
reliable  judgment  as  to  the  probable  result,  for  there  are  many  grave 
questions  involved  besides  the  ability  to  resist  rupture,  and  these  will 
inevitably  be  developed  under  the  strain  of  excessive  charges. 

For  a  long  time  the  question  of  casting  guns  in  a  solid  mass,  and  cool- 
ing them  from  the  exterior,  or  casting  them  hollow,  and  cooling  from  the 
interior,  upon  the  comprehensive  plan  of  Major  Eodman,  has  occupied 
the  attention  of  the  bureau ;  and  in  a  paper  presented  to  the  department 
on  the  subject,  under  date  of  May  17,  1864,  an  opinion  was  expressed 
decidedly  in  favor  of  the  latter  for  all  the  heavy  guns  of  the  navy. 

As  these  views  were  subsequently  fully  sustained  by  the  recorded 
opinions  of  the  best  authorities  of  the  army  and  navy,  and  of  the  founders 
to  whom  the  question  was  submitted,  the  official  sanction  of  the  depart- 
ment is  only  needed  to  enable  the  bureau  to  adopt  this  plan  of  founding 
in  future  all  the  cannon  for  the  navy  above  an  8-inch  calibre,  after  it  shall 
have  been  submitted  to  Admiral  Dahlgren.  It  may  be  remarked,  that 
Mr.  Parrott  has  recently  determined  to  manufacture  his  heavy  rifles  in 
this  way,  being  convinced  that  he  thereby  obtains  a  more  solid  gun,  of 
greater  uniform  strength,  and  a  surface  of  bore  better  suited  to  resist  the 
action  of  the  rifled  projectiles. 

It  would  no  doubt  be  interesting  to  describe  fully  the  process  of  found- 
ing cannon  by  both  methods  ;  but  the  limits  of  a  general  official  report 
on  various  other  subjects  render  this  inexpedient.  It  is  sufficient  to  know, 
however,  that  they  are  each  perfectly  understood  by  the  men  engaged  in 
the  business  ;  and  since  the  casting  of  the  enormous  20-inch  cannon  at 
Fort  Pitt  foundry  for  the  army  and  navy,  there  really  would  seem  to  be 


EXPERIMENTS    ON    HEAVY    ORDNANCE.  157 

no  limit  to  the  ambition  and  daring  of  OUT  artisans.  These  huge  masses 
of  iron  were  cast  without  the  slightest  difficulty,  the  time  elapsing  from 
the  moment  of  tapping  the  furnaces  to  the  complete  tilling  of  the  monld 
of  the  army  gun  being  only  22  minutes.  To  produce  this  casting  no  less 
than  105  tons  of  iron  were  melted. 

This  huge  cannon  having  been  bored  and  finished  and  the  test  speci- 
mens confirming  the  opinion  formed  of  the  soundness  of  the  metal  in 
working  under  the  tools,  it  has  been  recently  placed  in  battery  at  Fort 
Hamilton,  where  it  will  be  subjected  to  proof  at  an  early  day. 

From  the  report  of  the  Chief  of  Ordnance,  War  Department,  for  1865. 

The  importance  to  the  country  of  having  the  armaments  placed  in  the 
forts  as  rapidly  as  they  can  be  prepared  to  receive  them  is  so  evident, 
that  I  have  caused  the  manufacture  of  sea-coast  gun-carriages  to  be  con- 
tinued as  rapidly  as  practicable  at  the  two  arsenals  which  possess  the 
proper  facilities  for  making  them ;  and  orders  have  been  given  to  the 
several  founders,  who  have  been  engaged  in  making  heavy  guns  for  this 
department,  for  as  many  guns  as  carriages  can  be  made  for. 

I  have  been  informed  by  the  Chief  Engineer  that  he  will  be  prepared  to 
receive  guns  in  the  forts  faster  than  carriages  can  now  be  made,  and  it 
is  in  contemplation  to  increase  the  capacity  for  manufacturing  sea-coast 
carriages. 

Experimental  wrought-iron  field  and  siege  gun-carriages  have  also 
been  made  and  tested,  with  results  so  satisfactory  as  to  render  it  certain 
that  these  carriages  may  be  advantageously  substituted  for  the  wooden 
carriages,  and  it  is  proposed  to  make  no  more  gun-carriages  of  wood. 

The  smooth-bore  cannon  of  large  calibre  which  have  been  used  during 
the  war  have  given  satisfaction,  and  are  regarded  as  perfectly  reliable. 
The  great  importance  of  having  reliable  rifled  guns  of  large  calibre  is 
universally  admitted,  and  the  attention  of  this  government,  and  of  the 
nations  of  Europe,  has  been  directed  to  that  object ;  but  so  far,  it  is 
believed,  without  entire  success  in  its  accomplishment. 

The  many  failures,  by  bursting,  of  the  celebrated  Parrott  guns  in  the 
land  and  naval  service  have  weakened  confidence  in  them,  and  make  it 
the  imperative  duty  of  this  department  to  seek  elsewhere  for  a  more  reli- 
able rifle  gun. 

Mr.  Horatio  Ames,  of  Falls  Village,  Connecticut,  invented  a  plan  of 
making  wrought-iron  guns,  which  many  believe  would  possess  those 
qualities  which  are  so  very  desirable  for  guns  of  heavy  calibre,  and 
although  the  cost  of  these  guns  was  necessarily  very  great  in  comparison 
with  the  cost  of  cast-iron  guns,  a  conditional  order  was  given  to  Mr. 
Ames  to  manufacture  15  of  them  for  the  government,  the  condition 
being  that  the  guns  should  be  superior  to  any  rifled  guns  in  the  service. 
One  of  these  guns  was  fired  under  the  direction  of  a  board  of  officers, 
who  unanimously  expressed  the  opinion  that  the  "Ames  wrought-iron 
guns  possess,  to  a  degree  never  before  equalled  by  any  cannon  of  equal 
weight  offered  to  our  service,  the  essential  qualities  of  great  lateral  and 
longitudinal  strength,  and  great  powers  of  endurance  under  heavy 
charges ;  that  they  are  not  liable  to  burst  explosively  and  without  warn- 
ing, even  when  fired  under  very  high  charges ;  and  that  they  are  well 
adapted  to  the  wants  of  the  service  generally,  but  especially  whenever 
long  ranges  and  high  velocities  are  required."  The  board  also  expressed 
the  opinion  that  the  15  Ames  7 -inch  guns  possessed  sufficient  weight 
and  strength  to  receive  an  8-inch  bore,  and  recommended  that  the  gun 
which  had  been  fired  under  their  direction  should  be  reamed  up  to  eight 
inches  and  subjected  to  further  trial. 


158          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

They  further  decidecUthat  Mr.  Ames  had  fulfilled  the  obligation  incur- 
red by  him  in  his  contract  to  furnish  the  gun,  and  that  so  many  of  the 
guns  as  should  endure  a  proof  of  10  rounds  with  the  service  charge,  and 
pass  the  proper  inspection,  should  be  accepted  and  paid  for. 

Two  of  the  14  guns  burst  in  proof,  exhibiting  serious  defects  in 
their  manufacture — defects  in  welding — which  I  had  been  apprehensive 
could  not  be  avoided.  The  guns  which  endured  the  proof  of  10  rounds 
were  accepted  and  paid  for  by  this  department. 

The  gun  which  was  fired  under  the  direction  of  the  board  was  bored 

up  to  eight  inches  and  fired  24  times  with  service  charges,  when  it  burst. 

###*##*# 

Believing  that,  with  our  present  knowledge  of  the  properties  pf  metals 
and  our  skill  in  working  them,  reliable  rifle  guns  of  large  calibre  can  be 
made  of  cast  iron,  I  have,  with  your  sanction,  caused  a  pair  of  8-inch  rifle 
guns  of  the  supposed  proper  model  and  weight  to  be  made.  These  guns 
are  now  at  Fort  Monroe  undergoing  extreme  proof,  and  should  their 
endurance  be  satisfactory  it  is  proposed  to  have  other  guns  like  them 
made. 

From  the  report  of  tlie  Chief  of  Ordnance,  Navy  Department,  1865. 

THE  FOUNDRIES. 

The  presumption  is  that  the  number  of  serviceable  cannon  which  will 
be  found  by  survey,  together  with  those  now  being  received  from  the 
contractors,  will  be  amply  sufficient  to  meet  the  wants  of  the  navy  for 
several  years,  and  therefore  the  bureau  does  not  contemplate  entering 
into  any  new  contracts  for  guns.  The  experience  of  the  war  has  demon- 
strated that  we  can  rely  upon  the  private  enterprise  of  our  citizens  to 
produce  good  cannon,  and  as  rapidly  as  they  are  wanted.  Therefore  no 
apprehension  need  be  entertained  of  any  difficulty  arising  from  the 
suspension  of  this  work  for  the  navy,  and  the  return  of  these  large  work- 
shops to  producing  machinery  and  tools  for  commerce  and  the  arts ;  on 
the  contrary,  they  will  be  better  prepared  with  their  acquired  knowledge 
to  enter  at  once  upon  the  work,  and  to  manufacture  either  such  guns  as 
are  now  in  use,  or  upon  any  other  models  which  future  experiments  may 
prove  to  be  better  adapted  for  naval  use.  I  of  course  have  now  especial 
reference  to  cast-iron  cannon,  both  smooth-bored  and  rifled,  and  to  the 
manufacture  of  bronze  howitzers ;  for  the  art  of  fabricating  wrought-iroii 
or  steel  cannon  is  yet  in  its  infancy  here,  and  remains  an  unsettled  ques- 
tion abroad,  only  to  be  solved  by  a  well-conducted  series  of  careful  experi- 
ments. So  far,  the  results  obtained  by  private  enterprise  in  this  country 
are  very  doubtful,  and  by  no  means  to  be  relied  upon.  In  fact,  the  difficul- 
ties of  the  problem  are  very  much  increased  by  the  persistent  efforts  of 
inventors  to  produce  wrought-iron  or  steel  rifled  ordnance  of  large  calibre, 
instead  of  confining  the  preliminary  trials  to  smooth-bore  guns  of  the 
ordinary  size. 

It  should  be  remembered  also  that  the  advantages  claimed  for  rifled 
cannon  over  smooth-bores  are  in  many  respects  visionary,  and  do  not 
bear  the  test  of  actual  conflict,  much  less  the  more  elaborate  and  quietly 
pursued  experiments  of  the  practice  ground  j  and  that  whatever  of  extra- 
ordinary power  or  range  may  be  obtained  with  them,  is  generally  quali- 
fied in  a  great  degree  by  the  danger  of  premature  rupture,  under  the 
strain  of  excessive  charges  and  heavy  projectiles  necessary  to  produce 
such  effects,  and  this  whether  the  rifles  are  made  of  cast  iron,  wrought 
iron,  or  steel. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  159 

During  the  recent  rebellion  the  cast-iron  smooth-bore  guns  of  the  navy 
endured  all  of  the  severe  service  to  which  they  were  subjected,  and  proved 
their  excellence  everywhere  and  under  all  the  conditions  of  actual  war. 
Not  a  single  gun  of  the  Dahlgren  system  has  burst  "prematurely;  and 
none  of  the  15-inch  guns,  even  when  fired  with  their  heaviest  charges, 
have  ever  failed  except  in  the  case  of  two  or  three  which  had  their  muzzles 
ruptured  by  the  premature  explosions  of  shells,  the  body  of  the  gun  even 
then  remaining  uninjured.  For  the  ordinary  warfare  of  wooden  ships 
against  each  other,  or  against  forts,  these  smooth-bore  guns  are  undoubt- 
edly the  best  of  their  kind;  while  the  practice  at  the  test  battery  against 
armor  plating  shows  that  even  the  11 -inch  at  close  quarters  is  capable 
of  piercing  any  thickness  of  iron  or  steel  with  which  the  sides  of  an  ordi- 
nary cruiser  intended  to  keep  the  seas  could  be  covered  with  safety,  and 
this  without  any  danger  of  rupture  from  the  use  of  increased  charges, 
unless  the  gun  has  been  very  much  weakened  by  previous  service. 

The  cast-iron  rifled  ordnance,  manufactured  by  Mr.  Parrott,  of  the 
West  Point  foundry,  for  the  navy,  did  also  good  service  within  their 
sphere,  and  justly  merited  all  the  confidence  placed  in  them,  until  it  was 
rudely  shaken  by  the  disastrous  rupture  of  several  100  and  150-pounders 
during  the  naval  bombardment  of  Fort  Fisher. 

Prompt  measures  were  immediately  taken  to  ascertain,  if  possible,  the 
cause  of  these  failures,  and  a  board  of  ordnance  officers,  convened  by 
order  of  the  bureau,  investigated  the  subject  in  all  its  bearings.  Their 
final  report  is  hereto  appended.  . 

Without  waiting,  however,  for  the  decision  of  this  board,  the  bureau 
directed  the  removal  of  the  150-pounders  from  service  entirely,  and  re- 
duced the  charge  of  the  100-pounders  to  8  pounds  of  powder  and  a  shell 
of  80  pounds.  This  reduction,  and  the  gun  confined  to  the  work  for 
which  it  was  intended,  and  not  used  for  every  occasion,  especially  where 
the  smooth-bores  are  more  available,  will,,  it  is  believed,  prevent  the 
occurrence  of  premature  rupture  in  future,  provided,  however,  that  the 
express  and  oft-repeated  injunctions  in  relation  to  the  use  of  rifled  guns  are 
strictly  observed. 

The  settled  policy  of  the  bureau  is,  at  present,  to  arm  our  vessels  with 
a  mixed  battery  of  pivot  and  broadside  smooth-bore  guns,  governed  with 
reference  to  calibre  by  the  capacity  and  deck  accommodation  of  individ- 
ual ships.  The  rifled  guns  are  exceptional,  and  are  intended  simply  as 
chase  guns  where  long  range  is  required,  or  to  be  used  at  great  distances 
in  repelling  the  attack  of  smaller  and  swifter  opponents  armed  with 
similar  pieces. 

The  idea  of  a  broadside  armament  composed  exclusively  of  rifled  guns 
is  by  no  means  warranted  by  the  experience  of  the  past  war,  and  with 
the  gathered  strength  and  prestige  of  our  navy  we  can  aiford  to  await 
the  results  of  the  trials  now  going  on  in  England  and  elsewhere,  to  bring 
forward  a  rifled  gun  of  large  calibre  which  can  be  trusted  and  used  as  a 
substitute  for  the  smooth-bores  in  broadside  or  pivot.*  Time,  and  a  pro- 
digious expenditure,  with  corresponding  successful  results,  are  needed 
to  satisfy  ordnance  men  that  the  progress  of  science  in  the  fabrication 
of  "built-up"  guns,  whether  composed  wholly  of  wrought-iron,  or  of  steel 
and  wrought-iron  combined,  can  produce  either  a  rifled  or  smooth-bored 
cannon  which  will  take  the  place  of  our  present  comparatively  inexpen- 
sive cast-iron  ordnance  so  far  as  endurance  even  is  concerned.  And 
when  this,  the  first  essential,  is  determined  conclusively,  there  remain 
the  other  important  questions  between  the  smooth-bore  and  rifle  of  accu- 

*  Breech-loading  cannon  made  of  steel,  by  Krupp,  are  now  being  tried  in  Prussia  and 
Russia,  but  they  find  no  favor  in  England. 


160          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

racy  at  all  available  ranges,  penetration,  shock,  and  the  certainty  of 
ricochet  fire.  And  in  illustration  of  the  advantage  of  this  latter  condi- 
tion of  licochet  fire,  as  being  peculiarly  the  property  of  smooth-bore,  I 
may  refer  to  the  published  report  of  the  army  operations  against  Charles- 
ton, in  which  the  commanding  general  bears  testimony  to  the  magnificent 
practice  made  by  the  iron-clad  frigate  New  Ironsides  with  her  11-iuch 
guns  against  Fort  Wagner.  He  says,  in  speaking  of  the  final  operations 
against  that  work:  a Thirteen  of  our  heavy  Parrott  rifles,  100,  200,  and 
300-pounders,  pounded  away  at  short  though  regular  intervals  at  the 
southwest  angle  of  the  boomb-proof,  while,  during  the  day-time,  the  New 
Ironsides,  with  remarkable  regularity  and  precision,  kept  an  almost 
incessant  stream  of  11-inch  shells  from  her  eight-gun  broadside  ricochet- 
ing over  the  water  against  the  sloping  parapet  of  Wagner,  whence,  de- 
flected upwards  with  a  low  remaining  velocity,  they  dropped  vertically, 
exploding  within  or  over  the  work,  and  rigorously  searching  every  part 
of  it  except  the  subterranean  shelters." 

A  ricochet  fire  of  this  kind  is  simply  impossible  from  rifled  guns  with 
elongated  projectiles,  whatever  may  be  said  of  their  superior  powers  of 
penetration. 

But  the  first  essential  of  endurance  in  these  " built-up"  guns  is  by  no 
means  an  accomplished  fact,  and  in  the  development  of  any  great  power 
which  they  ought  to  possess  by  using  heavy  charges,  they  have  hitherto 
developed  also  an  inherent  weakness  which  the  greatest  care  in  the  pre- 
paration and  fabrication  of  the  materials  of  which  they  are  composed  is 
unable  to  overcome.  A  single  gun  may  now  and  then  be  made  which 
will  show  remarkable  endurance  under  protracted  firing;  but  a  second 
or  third,  fabricated  apparently  like  the  first,  yields  prematurely,  and  dis- 
appoints the  inventor  when  he  least  expects  it  With  cast-iron  ordnance, 
however,  uniformity  of  endurance  can  be  obtained  even  with  rifles,  as  is 
exemplified  by  the  trials  of  the  three  100  pounders  by  the  board  on  rifled 
ordnance,  at  Cold  Spring,  New  York. 

We  may,  therefore,  content  ourselves  with  the  possession,  at  least,  of 
a  system  of  smooth-bore  and  rifled  ordnance  which  has  stood  the  test  of 
no  ordinary  conflict;  and  that  we  have  every  reason  to  expect  that  ample 
leisure  will  be  afforded  us  in  the  future  for  the  examination  and  trial  of 
any  new  theories  which  may  be  presented  for  investigation. 

For  this  state  of  things  we  are  mainly  indebted  to  the  enterprise  of 
our  citizens  who  own  and  have  so  ably  conducted  the  cannon  foundries 
of  the  north. 

From  tlie  Report  of  the  Chief  of  Ordnance,  War  Department,  for  1866. 

The  experiments  which  have  been  carried  on  at  Fort  Monroe  arsenal 
to  test  the  power  and  endurance  of  the  8-inch  and  12-inch  rifle  guns, 
made  of  cast  iron,  by  this  department,  are  highly  satisfactory,  and  war- 
rant the  belief  that  cast-iron  rifle  guns,  of  these  calibres,  may  be  intro- 
duced into  the  military  service  with  safety  and  advantage.  The  12-inch 
rifle,  throwing  a  projectile  of  600  pounds,  and  with  55  pounds  of  powder, 
has  been  fired  390  times.  It  is  believed  that  no  rifle  gun  of  this  calibre 
has  ever  given  so  great  endurance.  The  further  trial  of  these  guns  will 
be  continued. 

#*#**## 

The  armament  of  our  fortifications  now  includes  3,546  serviceable 
cannon,  of  which  1,334  are  of  heavy  calibres,  (20, 15, 10  and  8-inch  bores) 
and  653  are  rifled  cannon. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  161 

From  the  Report  of  the  Chief  of  Ordnance,  Navy  Department,  for  1866. 

The  founding  of  cannon  by  either  of  the  methods  of  solid  or  hollow 
casting  has  been  fully  tried  in  this  country,  and  the  results  have  been 
highly  satisfactory.  Nothing  has  yet  transpired  abroad  in  the  efforts 
which  have  been  made  to  produce  better  guns  than  ours,  of  steel  alone, 
or  built  up  of  steel  and  wrought  iron,  to  induce  the  fear  that  cast-iron 
ordnance  will  be  surpassed  in  any  essential  of  endurance,  either  as 
smooth-bores  or  rifles.  As  a  notable  instance  in  this  connection,  it  may 
be  stated  that  an  army  cast-iron  Eodman  12-inch  rifle  has  been  fired  at 
Fortress  Monroe  nearly  400  times,  with  charges  of  powder  varying  from 
45  to  55  pounds,  and  shot  weighing  from  450  to  620  pounds.  The  gun 
still  endures  this  service  without  yielding.  The  bureau  therefore  hesi- 
tates to  recommend  any  expenditure  in  trials  with  built-up  guns. 

From  the  Report  of  the  Chief  of  Ordnance,  War  Department,  for  1867. 

I  stated  in  my  last  annual  report  that  the  work  of  arming  the  perma- 
nent fortifications,  and  of  increasing  their  efficiency  by  providing  guns 
of  large  calibre  and  replacing  the  perishable  wooden  carriages  by  dura- 
ble wrought-iron  carriages,  had  progressed  rapidly,  and  would  be  con- 
tinued as  fast  as  the  available  means  would  admit  until  all  the  light 
guns,  which  are  ineffective  against  iron-clad  vessels,  and  all  wooden  car- 
riages, should  have  been  superseded  by  the  most  durable  and  effective 
articles  of  their  respective  kinds. 

I  am  decidedly  of  opinion  that  this  should  be  done,  and  that  proper 
armaments  should  be  provided  and  placed  in  the  permanent  forts  as  fast 
as  they  are  prepared  to  receive  them. 

Heavy  guns  and  gun-carriages  cannot  be  provided  and  mounted  in 
the  forts  in  a  few  days  or  in  a  few  weeks,  and  if  this  government  should 
become  suddenly  involved  in  war  with  a  maritime  power,  or  if  war 
should  be  imminent,  the  country  would  not  be  satisfied  if  the  important 
forts  were  unprovided  with  their  proper  armaments,  and  would  demand 
the  reason  why  they  have  not  been  provided,  when  Congress  had  furn- 
ished the  necessary  means,  and  it  would  hold  the  War  Department 
responsible  for  the  failure. 

Entertaining  these  views,  I  have  felt  it  to  be  my  imperative  duty  to 
provide  guns  and  gun-carriages  for  the  permanent  forts  as  rapidly  as  the 
engineer  department  was  prepared  to  have  them  mounted,  and  as  the 
means  provided  by  Congress  would  admit. 

On  the  30th  of  June,  1866,  the  armaments  of  the  forts  included  3,546 
serviceable  cannon,  of  which  1,334  were  of  heavy  calibre,  (20, 15, 10.  and 
8  inches,)  and  6^3  rifled,  a  majority  of  the  guns  being  of  smaller  calibre 
than  eight  inches. 

It  is  known  that  smooth-bore  guns  of  less  calibre  than  eight  inches 
are  entirely  ineffective  against  iron-clad  war  vessels,  and  should  not 
constitute  a  part  of  the  armament  of  any  of  our  important  forts. 

In  December,  1866,  this  bureau  was  informed  by  the  engineer  depart- 
ment that  2,152  guns  of  heavy  calibre  (20,  15,  and  13-inch  smooth-bores 
and  10  and  12-inch  rifles)  would  be  required  during  the  year  1867,  or  as 
soon  as  they  could  be  furnished.  As  some  of  the  guns  which  were  asked 
for  were  of  calibres  and  kinds  which  had  not  been  adopted  for  our  ser- 
vice, I  requested  that  a  board  of  officers  might  be  instituted  to  deter- 
mine the  calibres,  the  number  of  each  calibre,  and  the  proportion  of 
rifle  guns  to  smooth-bores,  required  to  arm  the  permanent  forts. 

The  board,  which  was  composed  of  engineer,  ordnance,  and  artillery 
Eep.  No.  266 11 


162  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

officers,  were  unanimously  of  the  opinion  that  u  there  would  probably  be 
required  for  the  permanent  fortifications,  in  addition  to  the  ordnance 
now  on  hand,  805  smooth-bore  guns  of  20,  15,  and  13  inches  calibre,  810 
rifles  of  12  and  10  inches  calibre,  and  300  mortars  of  15  and  13  inches 
calibre,  to  be  provided  from  time  to  time,  as  the  readiness  of  the  forts 
to  receive  armament,  the  capacity  of  the  foundries  for  its  manufacture, 
and  the  appropriations  applicable  to  its  procurement,  may  warrant." 

This  recommendation  received  the  approval  of  the  Secretary  of  War 
ad  interim. 

None  of  these  guns  have  yet  been  provided,  and  there  are  no  existing 
orders  or  contracts  for  heavy  cannon. 

Some  of  the  forts  are  ready  to  receive  guns  of  13  inches  calibre,  and 
none  have  yet  been  provided.  It  is  worthy  of  consideration  whether 
some  should  not  be  provided  at  once  and  placed  in  the  forts  which  are 
ready  to  receive  them. 

This  department  recognizes  the  great  importance  of  providing  the  very 
best  and  most  reliable  heavy  guns  for  arming  the  forts,  and  has  used  all 
means  within  its  control  to  obtain  them. 

The  founders  have  not  been  allowed  to  use  any  but  the  best  gun  iron 
known  to  the  department,  and  it  has  been  required  that  the  metal  in 
every  gun  shall  fulfil  certain  established  conditions  with  respect  to  ten- 
sile strength,  density,  and  initial  strain.  A  large  number  of  guns  have 
been  condemned  before  reception  because  the  metal  did  not  fulfil  all  of 
the  prescribed  conditions.  These  requirements  have  produced  excellent 
results. 

Persistent  efforts  have  been  made  for  some  time  past  by  ignorant  or 
designing  persons  to  destroy  public  confidence  in  the  heavy  guns  which 
have  been  provided  by  the  ordnance  departments  of  the  army  and  navy. 

Iron  castings,  placarded  as  representing  the  condition  of  the  metal  in 
our  heavy  guns,  have  been  placed  in  conspicuous  public  places,  and 
publications  have  appeared  from  time  to  time  in  prominent  journals 
asserting  that  these  guns  were  worthless;  that  they  could  only  be  fired 
with  very  light  charges  of  powder,  and  that  they  would  burst  if  fired  a 
few  times  rapidly. 

These  attempts  to  injure  the  character  of  our  heavy  ordnance  undoubt- 
edly produced  some  effect  on  the  public,  and  increased  the  responsibili- 
ties of  this  bureau. 

From  the  report  of  the  Chief  of  Ordnance,  Navy  Department,  for  1867. 

Since  the  date  of  my  last  annual  report,  all  existing  contracts  for 
naval  cannon  have  been  completed  and  the  guns  delivered.  With  the 
exception  of  the  15-inch  guns,  it  is  believed  that  the  stock  on  hand  will 
meet  the  existing  wants  of  the  service.  There  is  also  a  superabundant 
supply  of  serviceable  projectiles  of  all  kinds,  together  with  a  sufficiency 
of  gunpowder,  to  meet  the  current  demands  of  our  cruisers. 

Kecent  trials  in  England  of  a  15-inch  gun  of  navy  pattern,  cast  on 
Rodman's  method,  have  fully  vindicated  the  wisdom  of  the  measure  of 
introducing  this  calibre  of  cast-iron  ordnance  into  our  service. 

From  the  report  of  the  Chief  of  Ordnance,  War  Department,  for  1868. 

In  the  last  annual  report  from  this  office  the  unanimous  opinion  of  the 
board  on  the  armament  of  fortifications,  composed  of  engineer,  ordnance, 
and  artillery  officers,  was  quoted,  showing  the  necessity  of  a  large  num- 
ber of  smooth-bore  and  rifle  cannon  for  such  armament. 

In  pursuance  of  this  opinion,  approved  by  the  War  Department,  and 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          163 

at  the  request  of  the  Chief  of  Engineers,  a  few  of  these  cannon  have  been 
ordered,  and  are  now  nearly  finished  and  ready  for  trial  to  test  their 
power  and  endurance.  It  will  be  necessary  to  have  a  considerable  num- 
ber of  cannon  manufactured  of  the  kinds  and  calibre  suitable  for  arming 
permanent  fortifications,  and  proportionate  to  the  numbers  they  are  now 
in  need  of  to  make  them  effective  against  the  most  formidable  attacks. 
As  the  preparation  and  completion  of  such  armaments  require  much 
time,  it  is  strongly  recommended  that  the  manufacture  of  the  smooth- 
bore cannon,  whose  power  and  endurance  are  well  established,  be  car- 
ried on,  and  that  of  the  rifle  cannon  also,  as  soon  as  the  results  of  the 
practical  tests  will  authorize  it,  as  fast  as  the  means  applicable  thereto 
will  admif. 

My  attention  having  been  called  by  the  Chief  of  Engineers  to  an  error 
in  my  annual  report  of  last  year,  in  which  I  say,  "  In  December,  1866, 
this  bureau  was  informed  by  the  engineer  department  that  2,152  guns  of 
heavy  calibre  (20,  15,  and  13 -inch  smooth-bores,  and  10  and  12 -inch 
rifles)  would  be  required  during  the  year  1867,  or  as  soon  as  they  can  be 
furnished."  I  take  occasion  to  say  that  the  letter  of  the  Chief  of  Engi- 
neers of  December  13, 1866,  which  was  before  me  when  the  paragraph  in 
my  report  was  written,  and  from  whictt  the  number  was  intended  to  be 
taken,  called  for  2,202,  and  that  a  subsequent  letter  from  the  Chief  of 
Engineers,  dated  January  25,  1867,  modified  and  reduced  the  number  of 
guns  called  for  from  2,202  to  1,915,  agreeing  with  the  number  recom- 
mended by  the  armament  board,  as  stated  by  me  in  my  annual  report 
for  1867,  and  approved  by  the  War  Department.  The  letter  of  the  Chief 
of  Engineers  of  January  25,  1867,  was  accidentally  overlooked  by  me, 
and  hence  the  error  in  my  report  as  to  the  number  of  guns  required  by 
the  engineer  department,  and  which  I  beg  leave  to  correct. 

I  believed  that  our  heavy  cast-iron  guns  were  the  cheapest  and  most 
effective  guns  that  were  possessed  by  any  nation,  and  experiments  made 
to  test  their  power  and  endurance  have  shown  that  it  is  so. 

The  20-inch  gun  has  been  fired  with  a  charge  of  200  pounds  of  powder 
and  a  shot  weighing  1,100  pounds,  and  I  have  no  hesitation  in  saying 
that  this  may  be  the  regular  charge  for  this  gun.  The  range  at  25 
degrees  elevation  was  more  than  4£  miles. 

A  15-inch  gun  has  been  fired  as  follows,  viz : 

7  times  with  40  pounds  of  powder  and  a  shell  weighing  350  pounds, 

5  times  with  50  pounds  of  powder  and  a  shell  weighing  350  pounds. 

70  times  with  50  pounds  of  powder  and  a  shot  weighing  434  pounds. 

59  times  with  55  pounds  of  powder  and  a  shot  weighing  435  pounds. 

1  time    with  60  pounds  of  powder  and  a  shot  weighing  434  pounds. 

1  time   with  75  pounds  of  powder  and  a  shot  weighing  434  pounds. 

1  time   with  80  pounds  of  powder  and  a  shot  weighing  434  pounds. 

1  time    with  90  pounds  of  powder  and  a  shot  weighing  434  pounds. 

125  times  with  100  pounds  of  powder  and  a  shot  weighing  434  pounds. 

The  mean  range  obtained  with  100  pounds  of  powder  and  an  elevation 
of  32  degrees  was  7,732  yards. 

The  mean  initial  velocity  of  the  shot  with  the  same  charge  was  1,510 
feet  per  second. 

The  rounds  were  fired  in  35  minutes,  which  was  as  rapidly  as  the  gun 
could  be  fired  with  100  pounds  of  powder  and  a  solid  shot. 

There  is  no  enlargement  of  the  bore  from  firing  and  the  metal  has  not 
been  cut  away  by  the  powder. 

The  gun  appears  to  be  perfectly  serviceable  in  every  respect. 

A  15-inch  navy  gun  has  been  fired  12  times  in  16  minutes  with  40  and 
55  pounds  of  powder  and  solid  shot,  without  injury. 


164  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

A  number  of  15-inch  navy  guns  were  fired  in  action  several  hundred 
times,  and  some  of  them  with  60  pounds  of  powder  and  solid  shot.  The 
muzzles  of  two  of  them  were  blown  off  in  consequence  of  the  premature 
explosion  of  shells  in  the  bores.  No  other  injury  was  sustained  by  any 
of  the  guns. 

A  10-inch  gun,  the  metal  of  which  had  a  greater  strain  than  the  maxi- 
mum limit  which  had  been  established,  was  fired  as  follows,  and  without 
injury  to  the  gun,  viz : 

18  times  with  18  pounds  of  powder  and  a  shot  weighing  127  pounds. 

17  times  with  20  pounds  of  powder  and  a  shot  weighing  127  pounds. 

2  times  with  22  pounds  of  powder  and  a  shot  weighing  127  pounds. 

453  times  with  25  pounds  of  powder  and  a  shot  weighing  127  pounds. 

120  times  with  26  pounds  of  powder  and  a  shot  weighing  127  pounds. 
4  times  with  27  pounds  of  powder  and  a  shot  weighing  127  pounds. 
1  time  with  30  pounds  of  powder  and  a  shot  weighing  127  pounds. 

Only  one  12-inch  rifle  gun  has  been  made  for  this  department.  It  has 
been  fired  as  follows,  and  appears  to  be  entirely  serviceable,  viz : 

107  times  with  charges  of  powder  varying  between  35  and  85  pounds 
and  a  shell  weighing  477  pounds.  t 

341  times  with  charges  of  powder  varying  between  35  and  80  pounds 
and  a  solid  shot  weighing  620  pounds. 

With  50  pounds  of  powder  the  mean  initial  velocity  of  75  shot  was 
1,139  feet  per  second. 

These  guns  were  cast  hollow  and  cooled  from  the  interior. 

Their  cost  is  less  than  one-seventh  that  of  steel  or  wrought-iron  guns 
per  pound,  and  they  are  believed  to  be  more  uniform  in  the  quality  of 
the  metal  and  more  reliable  than  either  steel  or  wrought-iron  guns. 

No  other  heavy  guns  have  endured  such  proof  or  performed  so  much 
work  as  these  guns  have  done,  and  it  is  confidently  claimed  that  they 
are  the  cheapest,  most  reliable,  and  most  effective  heavy  guns  that  have 
yet  been  produced.  It  is  known  that  several  foreign  powers  have  pur- 
chased some  of  the  15-inch  smooth-bores  and  12-inch  rifles  in  this  country, 
and  that  at  least  two  nations  of  Europe  are  manufacturing  15-inch  cast- 
iron  guns  upon  the  plan  which  has  been  adopted  by  this  department. 

While  the  results  of  actual  trial  have  satisfactorily  demonstrated  the 
strength,  efficiency,  and  reliability  of  our  smooth-bore  cast-iron  cannon 
of  large  calibres,  and  similar  trials  have  warranted  the  same  expectations 
in  regard  to  rifled  cannon  of  cast  iron,  these  latter  have  not  as  yet  been 
tested  to  a  sufficient  extent  to  authorize  their  adoption  for  the  service  in 
preference  to  heavy  rifled  cannon  of  any  other  material.  I  should  not, 
therefore,  feel  justified  in  procuring  any  large  number  of  these  rifled 
cannon  at  present,  but  would  prefer  to  make  further  trials  with  such 
number  only  of  them  as  may  be  necessary  for  that  purpose,  and  to  await 
the  results  before  proceeding  to  procure  the  cannon  of  this  kind  which 
our  permanent  fortifications  will  require.  So  important  is  it,  in  my 
opinion,  that  these  trials  should  be  made,  that  I  earnestly  recommend 
that  two  10-inch  and  two  12-inch  rifle  guns  be  made  at  once  and  fired  to 
extremity,  to  test  their  power  and  endurance. 

From  the  report  of  the  Chief  of  Ordnance,  Navy  Department,  for  1868. 

Opinions  differ  quite  as  widely  in  regard  to  the  preferable  mode  of 
developing  ordnance  power;  whether  it  shall  be  by  smooth  or  rifled 
bores — by  loading  at  breech  or  muzzle — made  from  iron  cast,  or  wrought, 
or 'from  steel — solid  or  in  connected  parts;  the  relation  of  mass  to  velo- 
city is  also  unsettled.  In  fact,  the  question  involves  the  necessity  of 


EXPERIMENTS    ON   HEAVY   ORDNANCE.  165 

going  back  to  fundamental  principles,  and  starting  thence  by  well-con- 
ducted experiments. 

In  England  the  government  seems  to  have  been  satisfied,  at  first,  to 
abide  by  the  views  and  the  skill  of  the  distinguished  engineer  Armstrong ; 
but  after  a  large  experience  and  a  heavy  expenditure,  another  direction 
has  been  taken. 

In  one  of  the  recent  French  iron-clads,  (the  Belliqueuse,)  I  observed 
very  heavy  rifled  cannon  were  mounted — loading  at  the  breech — a 
system  that  has  now  lost  favor  with  the  English. 

*"  There  is  also  a  greater  inclination  to  rifle  cannon  in  England  and 
France  than  with  us  at  the  present  time — the  experiences  of  battle 
having  largely  corrected  that  tendency  in  our  navy. 

It  is  of  national  importance  that  these  questions  should  be  investigated 
in  the  only  way  that  their  nature  permits — that  is,  by  experiment. 

We  cannot  take  the  conclusions  of  foreign  powers,  even  if  it  were  pos- 
sible to  know  what  they  agree  upon ;  but  we  must  search  for  ourselves 
and  be  able,  as  well  at)  others,  to  carry  the  experience  of  the  practice 
ground  into  battle. 

It  is  true  that  no  pressing  occasion  seems  to  demand  an  immediate 
exertion.  We  are  at  peace,  and  there  is  no  sign  of  a  war  to  which  we 
need  be,  or  are  likely  to  be,  a  party.  But  the  great  European  family  of 
nations  is  alive  with  the  apprehension  of  approaching  war,  and  no  one 
can  say  at  what  instant  its  vast  armies  may  be  precipitated  into  deadly 
conflict.  When  this  comes  it  cannot  be  art  internal  struggle,  but  will 
extend  wherever  the  commerce  or  the  distant  possessions  of  civilization 
are  to  be  found. 

Even  so  great  a  nation  as  the  United  States  may  be  denied  the  priv- 
ilege of  neutrality.  Orders  in  council  and  imperial  decrees  will  again,  as 
of  old,  revive  no  peaceful  discussion  of  the  rights  of  belligerent  and 
neutral  which  are  involved  in  the  practice  of  search,  of  blockade,  and 
of  contraband  of  war.  How  then  shall  our  flag  protect  its  neutral  rights 
against  the  strong  hand  of  the  aggressor  in  every  sea,  if  not  by  its 
ability  to  resist  injustice  when  committed? 

Even  the  ordinary  intercourse  of  peace  frequently  requires  the  inter- 
vention of  our  naval  representative  which,  judiciously  afforded,  prevents 
accidental  misunderstanding  from  acquiring  importance  by  delay. 

The  policy  of  the  country  always  has  been,  and  should  be  adhered  to, 
that  however  small  our  naval  force  in  peace,  every  vessel  of  it  shall  com- 
bine in  itself  the  highest  known  qualities  of  a  ship  of  war  in  armament, 
speed,  and  personnel.  Then,  in  case  of  an  emergency,  it  will  not  be  diffi- 
cult to  multiply  these  types  to  any  extent. 

As  ordnance  is  the  distinguishing  feature  in  this  question,  I  hope  that 
Congress  will  bestow  the  means  which  are  now  necessary  to  determine 
what  it  shall  be  when  iron-clads  become  the  objects  of  fire. 

From  the  report  of  Rear-Admiral  Porter  of  the  first  attack  on  Fort  Fisher. 

One  or  two  leading  vessels  having  made  the  mistake  of  anchoring  too 
far  off,  caused  those  coming  after  them  to  commit  a  like  error  $  but  when 
they  all  got  in  to  place  and  commenced  work  in  earnest,  the  shower  of  shell 
(115  per  minute)  was  irresistible.  So  quickly  were  the  enemy's  guns 
silenced  that  not  an  officer  or  man  was  injured.  I  regret,  however,  to 
have  to  report  some  severe  casualties  by  the  bursting  of  100-pounder 
Parrott  cannon. 

One  burst  on  board  the  Ticonderoga,  killing  six  of  the  crew  and 
wounding  seven  others.  Another  burst  on  board  the  Yantic,  killing  one 
officer  and  two  men.  Another  on  the  Juniata,  killing  two  officers,  and 


166  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

wounding  and  killing  ten  others.  Another  on  the  Mackinaw,  killing  one 
officer  and  wounding  five  others  (men.)  Another  on  the  Quaker  City, 
wounding,  I  believe,  two  or  three.  Another  ontheSusquehamia,  killing 
and  wounding  seven,  I  think. 

The  bursting  of  the  guns  (six  in  all)  much  disconcerted  the  crews  of 
the  vessels  when  the  accident  happened,  and  gave  one  and  all  a  great 
distrust  of  theParrottlOO-pounders,  and  (as  subsequent  events  proved) 
they  were  unfit  for  serviceman  d  calculated  to  kill  more  of  our  men  than 
those  of  the  enemy. 

From  the  report  of  Rear-Admiral  Porter  of  the  second  attack  on  Fort  Fisher. 

I  believe  we  have  burst  all  the  rifled  guns  left  in  the  fleet — one  on  the 
Susquehanna,  one  on  the  Pequot,  and  one  on  the  Osceola — and  I  think 
the  reputation  of  these  guns  is  now  about  ruined. 


WASHINGTON,  D.  C.,  February  6, 1867. 

SIR:  I  have  the  honor  to  transmit  herewith  the  "Proceedings  of  a 
board  of  officers  convened  by  virtue  of  Special  Orders  No.  29,  War  Depart- 
ment, Adjutant  Generals7  office,  Washington,  January  18,  1867." 
Yery  respectfully,  vour  obedient  servant, 

T.  G.  BAYLOR, 
Captain  of  Ordnance  and  Bvt.  Col.  U.  8.  A.,  Recorder. 

Brevet  Major  General  L.  THOMAS, 

Adjutant  General  U.  $.  A.,  Washington,  D.  C. 


Proceedings  of  a  board  of  officers  convened  in  virtue  of  Special  Orders  No. 
29,  War  Department,  Adjutant  General's  office,  Washington,  January  18, 
1867. 

Proceedings  of  a  board  of  officers  assembled  at  Washington,  D.  C.,  in 
pursuance  of  the  following  order,  viz : 

[Special  Orders  No.  29— Extract.] 

WAR  DEPARTMENT,  ADJUTANT  GENERAL'S  OFFICE, 

Washington,  January  18,  1867. 

#  *  #  *  #  #  * 

15.  A  board  of  officers  is  hereby  instituted  for  the  purpose  of  determining  the  calibres,  the 
number  of  each  calibre,  and  the  proportion  of  rifled  guns  which  will  probably  be  required 
for  the  armament  of  fortifications. 

Brevet  Brigadier  General  William  Maynadier,  ordnance  department;  Brevet  Major  Gen- 
eral W.  F.  Barry,  colonel  2d  U.  S.  artillery;  Brevet  Major  General  J.  G.  Barnard,  corps 
of  engineers;  Brevet  Major  General  H.  J.  Hunt,  lieutenant  colonel  3d  U.  S.  artillery; 
Brevet  Major  General  H.  G.  Wright,  corps  of  engineers ;  Brevet  Colonel  T.  G.  Baylor, 
ordnance  department.  The  board  will  meet  at  such  time  and  place  in  this  city  as  may  be 
designated  by  the  senior  member.  The  junior  member  will  record  the  proceedings. 

*  *  ,  *  *  *  *  * 

By  order  of  the  Secretary  of  War : 

E.  D.  TOWNSEND, 
Assistant  Adjutant  General. 

WASHINGTON,  January  24, 1867. 

The  board  met  in  pursuance  of  the  above  order,  and  on  the  call  of  the 
senior  member,  at  room  No.  47  in  the  Ordnance  Bureau,  at  11  o'clock  a.  in. 

Present:  1.  Brevet  Brigadier  General  Win.  Mayuadier;  2.  Brevet 
Major  General  H.  J.  Hunt  5  3.  Brevet  Major  General  H.  G.  Wright. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          167 

Absent:  1.  Brevet  Major  General  W.F.Barry;  2.  Brevet  Major  Gene- 
ralJ.  G.  Barnard;  3.  Brevet  Colonel  T.  G.  Baylor.  (Reasons  not  known.) 
After  some  discussion  in  relation  to  the  information  which  should  be 
procured  for  the  use  of  the  board  from  the  Engineer  and  Ordnance 
Bureaus,  the  board,  in  consequence  of  the  absence  of  the  three  remaining 
members,  adjourned  at  11.50  a.  m.,  to  meet  at  11  a.  m.  to-morrow. 

H.  G.  WEIGHT, 
Brevet  Major  General,  Recorder. 

WASHINGTON,  January  25, 1867. 

The  board  met  pursuant  to  adjournment. 

Present:  1.  Brevet  Brigadier  General  Wm.  Maynadier;  2.  Brevet 
Major  General  J.  G.  Barnard;  3.  Brevet  Major  General  H.  J.  Hunt;  4. 
Brevet  Major  General  H.  G.  Wright;  5.  Brevet  Colonel  T.  G.  Baylor. 

Absent:  1.  Brevet  Major  General  W.  F.  Barry.     (Eeason  not  known.) 

Brevet  Major  General  J.  G.  Barnard  and  Brevet  Colonel  T.  G.  Baylor 
reported  themselves  as  having  been  detained  by  interruption  of  travel. 

The  proceedings  of  the  previous  day  having  been  read,  some  discus- 
sion was  had  with  regard  to  the  meaning  of  the  order  assembling  the 
board,  as  to  whether  other  than  rifled  guns  were  to  be  considered.  It 
was,  however,  ascertained  by  reference  to  the  letters  of  the  Chief  of 
Engineers  and  Chief  of  Ordnance,  which  brought  forth  the  order  conven- 
ing the  board,  that  both  smooth-bore  and  rifled  guns  were  contemplated. 

The  communication  marked  A,  accompanying  these  proceedings,  was 
read,  having  been  referred  to  the  board  by  the  Chief  of  Ordnance. 

The  board  then  adjourned  till  Monday,  January  28,  at  11  a.  m.,  to 
await  information  from  the  engineer  department  with  reference  to  the 
present  armament  of  fortifications,  and  also  the  arrival  of  Brevet  Major 
General  W.  F.  Barry. 

WASHINGTON,  January  28, 1867. 

The  board  met  pursuant  to  adjournment,  and  the  proceedings  of  the 
previous  day  were  read,  all  the  members  being  present. 

Brevet  Major  General  W.  F.  Barry  reported  that  he  did  not  receive 
the  order  convening  the  board  in  time  to  reach  here  sooner. 

The  board,  after  examining  into  and  discussing  the  question  of  the 
calibres  of  guns  required  for  our  permanent  works,  adjourned  at  2  p.  m. 
until  12  in.  to-morrow,  to  await  further  information  from  the  engineer 
department. 

WASHINGTON,  January  29, 1867. 

The  board  met  pursuant  to  adjournment. 

Present  all  the  members.  The  board,  after  some  discussion,  unani- 
mously recommend  that  the  calibres  of  the  heavy  ordnance  hereafter  to 
be  provided  for  the  armament  of  permanent  fortifications  shall  be:  for 
smooth-bore,  20-inch,  15-inch,  and  13-inch  guns,  and  13-inch  and  15-inch 
sea-coast  mortars;  for  rifled  guns,  12-inch  and  10-inch;  and  that  guns  of 
other  than  the  above  calibres  now  on  hand  be  used  in  the  positions  for 
which  they  may  be  most  suitable ;  or  in  their  present  positions  until  they 
can  be  replaced  by  guns  of  the  calibres  above  specified. 

Major  General  J.  G.  Barnard  offered  the  folio  wing 'resolution,  which 
was  adopted  by  the  board,  viz : 

Resolved,  That,  in  the  opinion  of*  the  board,  mortars  may  be  made  to 
play  an  important  part  in  the  defence  of  channels,  as  well  as  in  prevent- 
ing anchorage ;  and  that,  to  ascertain  what  conditions  are  necessary  to 


168  EXPERIMENTS  ON  HEAVY  ORDNANCE.  • 

their  efficiency,  experimental  firings  should  be  made  to  determine  what 
force  of  iinpcct  is  necessary  to  break  through  the  best  protected  decks 
of  iron-clad*. 

The  above  resolution  was  amended  by  Brigadier  General  William  May- 
nadier,  and  the  amendment  adopted  by  the  board,  as  follows :  Resolved, 
further,  That,  in  the  opinion  of  the  board,  it  is  of  the  highest  importance 
that  experiments  should  be  made  to  ascertain  the  absolute  relative  power 
and  efficiency  of  the  20-inch  and  15-inch  smooth-bore  guns,  and  of  the 
12-inch  and  10-inch  rifled  guns,  against  monitors  and  iron-clad  vessels. 

At  3.15  p.  m.  the  board  adjourned  till  12  m.  to-morrow,  and  directed 
the  recorder  to  procure  a  copy  of  the  report  of  the  board  on  armament 
of  fortifications,  made  February  14,  1862,  and  approved  by  the  honor- 
able Secretary  of  War  March  27,  1862. 

WASHINGTON,  January  30, 1867. 

The  board  met  pursuant  to  adjournment ;  all  the  members  present. 
The  proceedings  of  the  previous  day  were  read.  Major  General  Barnard 
then  offered  the  following  resolution,  which  was  adopted,  viz: 

Resolved,  That  it  is  not  expedient  for  this  board  to  recommend  the 
construction  of  any  more  20-inch  guns  for  service  until  their  endurance 
and  capabilities  have  been  experimentally  demonstrated.  On  motion  it 
was  resolved  that  in  the  opinion  of  the  board,  the  Gatling  gun,  or  a  gun 
of  similar  character,  may  be  advantageously  adopted  in  place  of  the 
present  flank  defence  howitzer. 

The  board  resolved  to  take  up  the  plans  of  the  fortifications  in  New 
York  harbor  for  minute  examination,  in  order  to  determine  the  general 
principles  which  shall  govern  in  fixing  the  proper  positions  for  rifle 
cannon,  and  thus  enable  them  to  arrive  at  the  proper  proportion  of  such 
guns. 

The  board  then  adjourned  till  12  m.  to-morrow  to  wait  for  these  plans. 

WASHINGTON,  January  31,  1867. 

The  board  met  pursuant  to  adjournment,  and  the  proceedings  of  the 
previous  day  read.  On  motion  it  was  resolved  that  a  committee  of  three, 
to  consist  of  one  ordnance,  one  engineer,  and  one  artillery  officer,  be 
appointed  by  the  senior  officer  of  the  board  to  examine  into  such  details 
of  the  plans  of  fortifications,  and  of  the  character  of  the  approaches 
thereto,  as  may  indicate  the  proper  kind  of  guns,  whether  rifled  or  smooth- 
bore, to  be  placed  in  position,  and  to  report  the  result  of  their  examina- 
tion to  the  board  as  soon  as  practicable.  The  following  named  officers 
were  appointed  the  committee  by  the  senior  officer  of  the  board,  viz : 

1.  Brevet  Major  General  H.  J.  Hunt. 

2.  Brevet  Major  General  H.  G.  Wright. 

3.  Brevet  Colonel  T.  G.  Baylor. 

The  board  then  adjourned,  at  1  o'clock  p.  m.,  until  the  committee  were 
ready  to  report. 

WASHINGTON,  January  31,  1867. 

The  committee  met  in  room  No.  9  of  the  Engineer  Bureau,  at  1.30  p. 
m.,  and  proceeded  to  examine  the  maps  and  plans  of  the  forts  designed 
for  the  defence  of  New  York  harbor.  The  armament  for  which  pro- 
visions are  already  made  or  will  soon  be  finished,  for  the  forts  at  Sandy 
Hook  and  the  battery  near  Fort  Hamilton,  was  then  fixed  as  follows: 

Sandy  Hook. — Sixty-nine  10-inch  rifles,  thirty- six  13-inch  smooth-bore 
guns. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  169 

Battery  near  Fort  Hamilton. — Fifteen  12-inch  rifles,  two  10-inch  rifles, 
fourteen  15-inch  smooth-bore  guns. 

The  committee,  at  4.15  p.  m.,  adjourned  to  meet  at  the  same  place  at 
11  a.  m.  to-morrow. 

WASHINGTON,  February  1, 1867. 

The  committee  met  pursuant  to  adjournment,  all  the  members  present, 
and  resumed  the  consideration  of  the  armament  of  the  forts  for  the 
defence  of  New  York  harbor.  The  following  armament  was  agreed 
upon : 

Fort  Wadsworth. — Seventy-eight  10 -inch  rifles,  forty- three  13-inch 
smooth-bore  guns,  one  10-inch  smooth-bore  gun. 

South  Cliff  battery. — Eleven  12-inch  rifles,  eight  15-inch  smooth-bore 
guns. 

Battery  Hudson. — Ten  12-inch  rifles,  twelve  15-inch  smooth-bore  guns, 
two  10-inch  smooth-bore  guns. 

North  Cliff  battery. — Twenty  15-inch  smooth-bore  guns. 

Castle  Williams. — Five  15-inch  smooth-bore  guns. 

Fort  Columbus. — Six  12-inch  rifles,  four  10-inch  rifles,  seven  15-inch 
smooth-bore  guns,  four  13-inch  smooth-bore  guns. 

South  battery. — Four  10-inch  rifles,  three  13-inch  smooth-bore  guns. 

Fort  Wood. — Seventeen  10-inch  rifles,  eleven  15-inch  smooth-bore  guns. 

Fort  Gibson. — Four  12-inch  rifles. 

Fort  Schuyler. — Eight  12-inch  rifles,  fifty -three  10-inch  rifles,  four  15-, 
inch  smooth-bore  guns,  seven  13-inch  smooth-bore  guns. 

The  committee,  at  2.30  p.  m.,  adjourned  till  11  a.  m.  to-morrow. 

WASHINGTON,  February  2, 1857. 

The  committee  met  pursuant  to  adjournment,  all  the  members  present, 
and  after  the  proceeedings  of  the  previous  day  were  read,  fixed  upon 
the  armament  of  the  fort  at  Willet's  Point  as  follows : 

Fort  at  Willet's  Point. — Eighteen  12-inch  rifles,  nineteen  15-inch  smooth- 
bore guns. 

This  completed  the  examination  of  the  forts  for  the  defence  of  New 
York  harbor. 

The  committee  find,  upon  examination,  that  the  x>roportion  of  rifled  to 
smooth-bore  guns  thus  determined  upon  is  15  to  13 ;  but  they  would 
deem  an  equal  division  to  be  about  the  best  distribution  that  could  be 
made  from  their  present  knowledge  of  the  capabilities  of  the  two  kinds  of 
guns. 

The  committee  having  finished  the  business  before  it,  notified  the 
senior  member  of  the  board  that  they  would  be, ready  to  submit  their 
report  to  the  board  in  full,  session  on  Monday  next,  February  4,  1867. 
The  committee  then  adjourned  at  12.15  p.  m. 

WASHINGTON,  February  5, 1867. 

The  board  met  at  the  call  of  the  senior  member  at  room  No.  47  in  the 
Ordnance  Bureau  at  12  m.,  all  the  members  present.  The  proceedings 
and  report  of  the  committee  having  been  read,  the  senior  member  pro- 
posed the  question,  shall  the  report  of  the  committee  be  adopted"?  The 
vote  being  taken,  the  report  was  adopted  unanimously. 

The  following  remarks  were  then  presented  to  the  board  by  Brevet 
Major  General  J.  G.  Barnard: 

The  board  have  investigated  attentively  the  subject  submitted  to 
them  and  would  respectfully  state  that  the  problem  at  the  present 


170  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

moment,  "  What  shall  be  the  probable  absolute  number  of  different  cali- 
bres, and  what  shall  be  the  proportion  of  rifled  guns  required  for  our 
fortifications,"  is  peculiarly  indeterminate.  This  will  be  apparent  from 
the  following  considerations: 

Whenever  armament  boards  have  been  heretofore  convened,  their 
duties  have  been,  taking  as  fixed  the  number  and  emplacement  of  guns 
in  the  forts  and  batteries  as  prepared  by  the  engineer  department,  to 
determine  simply  what  guns  shall  be  placed  in  them.  In  the  case  of  the 
present  board,  however,  it  has  first  to  deal  with  an  entire  new  class  of 
guns,  of  far  greater  power  than  those  existing  when  the  number  of  exist- 
ing "emplacements"  was  fixed  by  the  engineer  department.  Second, 
with  casemates  and  platforms  not  intended  for  such  guns  and  generally 
illy  applicable  or  inapplicable  to  them.  Third,  the  modifications  required 
in  the  works  themselves,  to  enable  them  to  receive  our  new  guns  and  to 
resist  modern  artillery,  are  not  yet  determined  upon  by  the  engineer 
department,  though  in  course  of  experimental  investigation.  A  board 
of  engineers,  convened  by  the  honorable  Secretary  of  War  in  1864,  (and 
whose  proceedings  were  approved  by  him,)  to  investigate  the  modifications 
required  in  our  permanent  works,  recommended  very  important  changes 
in  the  disposition  of  guns  in  our  barbette  batteries,  suppressing  plat- 
forms, introducing  traverses,  &c. ;  while  they  at  the  same  time  emitted 
the  opinion  that  the  substitution  of  such  guns  as  the  15  inch  smooth- 
bore and  corresponding  rifle  would  justify  a  reduction  in  the  total  num- 
ber required.  At  the  same  time  we  believe  that  the  relative  capabilities 
of  the  smooth  bore  and  heavy  rifle  (of  heavy  ordnance)  have  not  been 
sufficiently  investigated,  experimentally,  to  enable  an  intelligent  decision 
to  be  made  as  to  the  best  proportion  to  be  adopted.  These  remarks  will, 
we  think,  show  conclusively  that  any  determination  of  the  "number  of 
each  calibre  an/1  proportion  of  rifled  guns  that  will  probably  be  required 
for  our  fortifications"  would  be  at  the  present  moment  very  illusory. 
The  board  have  therefore  contented  thenisejves  with  reviewing  the  dif- 
ferent ports  and  harbors  to  be  defended,  and  giving  such  a  judgment  as 
they  best  may,  attaching  no  value  to  it  as  an  ultimate  determination, 
but  merely  as  one  which  will  enable  the  ordnance  department  to  con- 
tinue in  the  best  probable  way  its  construction  of  guns. 

The  vote  having  been  taken  as  to  the  adoption  of  the  foregoing 
remarks,  resulted  as  follows: 

Ayes — Brevet  Major  General  W.  F.  Barry,  Brevet  Major  General  J. 
G.  Barnard,  Brevet  Major  General  H.  J.  Hunt,  Brevet  Major  General 
H.  G.  Wright,  Brevet  Colonel  T.  G.  Baylor— 5. 

Noes — Brevet  Brigadier  General  William  Maynadier — 1. 

The  board  is  unanimously  of  opinion  that  for  the  permanent  fortifica- 
tions there  will  probably  be  required,  in  addition  to  tiie  ordnance  now  on 
hand: 

15  20-inch  guns,  190  15-inch  gnus,  600  13-inch  guns,  smooth  bores';  200 
12-inch  guns,  610 10-inch  guns,  rifles ;  50  15-inch  mortars,  and  250 13-inch 
mortars;  to  be  provided  from  time  to  time  as  the  readiness  of  the  forts  to 
receive  armament,  the  capacity  of  the  foundries  for  its  manufacture,  and 
the  appropriations  applicable  to  its  procurement  may  warrant.  The 
board,  at  1.45  p.  m.,  adjourned  till  12  m.  to-morrow,  to  allow  the  recorder 
time  to  write  up  the  proceedings. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          171 

WASHINGTON,  February  6, 1867. 

The  board  met  pursuant  to  adjournment;  all  the  members  present. 
The  proceedings  having  been  read  to  the  board,  they  were  signed. 
The  board,  at  12.30  p.  m.,  adjourned  sine  die. 

WM.  MAYNADIEE, 
Brevet  Brigadier  General  U.  8.  Army. 

WILLIAM  F.  BAEEY, 
Colonel  2d  Artillery,  Brevet  Major  General. 

J.  G.  BAENAED, 
Colonel  of  Engineers,  Brevet  Major  General. 

HENEY  J.  HUNT, 
Brevet  Major  General.  Lieutenant  Colonel  2d  Artillery. 

H.  G.  WEIGHT, 
Lieutenant  Colonel  of  Engineers  and  Brevet  Major  General. 

T.  G.  BAYLOE, 
Captain  of  Ordnance  and  Brevet  Colonel  U.  8.  A. 


A. 


BALTIMORE,  MARYLAND, 

January  18,  1867. 


Whereas  the  duties  prescribed  to  this  board  involve  experimental 
tiring  to  determine  how  our  existing  works  are  to  be  modified,  and 
whereas  such  modifications  depend  upon  the  character  of  the  guns  to  be 
used ;  and  whereas  a  considerable  number  of  our  best  sea-coast  fortifica- 
tions are  already  constructed,  having  casemates  in  which  it  is  impossible 
by  any  modification  to  introduce  a  15-inch  gun  without  diminishing 
much  its  traverse  and  leaving  sections  without  casemate  fire;  and 
whereas,  the  English  experiments  show  that  the  Palliser  chilled  iron 
shot  is  the  most  formidable  projectile  against  iron  defences,  and  that  our 
own  iron  defences  will  be  attacked  by  such  or  by  steel  projectiles : 

Resolved,  That  it  be  represented  to  the  ordnance  department  that  it  is 
very  desirable  to  have  for  such  works,  and  perhaps  for  some  others,  a 
gun  of  nine  or  ten  inches  calibre,  which,  like  the  Woolwich  9-inch  gun, 
will  burn  40  or  more  pounds  of  powder,  and  throw  at  least  a  250-pound 
projectile.  Further, 

Resolved,  That  it  be  suggested  to  the  ordnance  department  that  pro- 
jectiles of  this  character  be  furnished  for  the  12  and  15-inch  guns  at 

Fort  Monroe  for  our  experimental  firing. 

»•••»'"*  *  *  * 

C.  B.  EEESE, 
Bvt.  Brig.  Gen.,  Captain  of  Engineers,  Recorder. 


ENGINEER  DEPARTMENT, 

January  22,  1867. 

Copy  respectfully  furnished  to  the  Chief  of  Ordnance  and  recommended 
for  favorable  consideration. 

A.  A.  HUMPHEEYS, 

Chief  of  Engineers. 


172  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

ORDNANCE  OFFICE, 

January  25,  1867. 

Respectfully  referred  to  the  board  on  the  armament  of  fortifications. 

A.  B.  DYER, 

Brevet  Major  General,  Chief  of  Ordnance. 
A  true  copy : 

T.  G.  BAYLOR, 
Captain  of  Ordnance  and  Brevet  Colonel  U.  S*A. 


[Endorsements.  ] 

WASHINGTON,  D.  0.,  February  6,  1867. 

T.  G.  Baylor,  captain  of  ordnance,  recorder,  transmits  proceedings  of 
a  board  of  officers,  of  which  Brevet  Brigadier  General  William  Maynadier 
was  president,  convened  to  determine  the  number  and  calibre  of  guns 
which  will  be  required  for  the  armament  of  fortifications. 
Respectfully  submitted  to  General  Grant. 

E.  D.  TOWNSEND, 

Assistant  Adjutant  General. 
ADJUTANT  GENERAL'S  OFFICE, 

February  7,  1867. 

HEADQUARTERS  ARMY, 

•    February  20,  1867. 

Respectfully  forwarded.    Approved. 

U.  S.  GRANT,  General. 

AUGUST  28,  1867. 
Approved  by  the  Acting  Secretary  of  War. 

ED.  SCHRIYER, 

Inspector  General. 

ADJUTANT  GENERAL'S  OFFICE, 

Washington,  September  4,  1867. 

Respectfully  referred  to  Brevet  Major  General  A.  B.  Dyer,  Chief  of 
Ordnance,  with  reference  to  the  approval  of  the  Secretary  of  War  en- 
dorsed hereon. 

E.  D.  TOWNSEND, 

Assistant  Adjutant  General. 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


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EXPERIMENTS  ON  HEAVY  ORDNANCE. 


EXPERIMENTS    ON   HEAVY    ORDNANCE.  175 

% 

APPENDIX  D. 

TECHNICAL  AND  MISCELLANEOUS  EXTRACTS. — INITIAL  TENSIONS. 

Extracts  from  u  experiments  on  metals  for  cannon  and  cannon  poivderj7 
*»        Rodman,  page  96. 

The  solid  gun,  cooling  from  the  exterior  in  an  open  pit,  and  being  of 
iron  that  contracted  very  much  in  cooling,  was  doubtless  thrown  upon  a 
very  heavy  strain,  the  exterior  being  compressed  and  the  interior  elon- 
gated $  while  the  hollow  gun,  being  rapidly  cooled  from  the  interior  and 
prevented  from  cooling  from  the  exterior,  was  thrown  upon  a  strain  just 
the  reverse  of  the  solid  one.  And  I  have  no  doubt  that  the  interior  of 
the  solid  gun  was  broken  before  the  exterior  was  relieved  from  the  pres- 
sure to  which  it  had  been  subjected  in  cooling;  while  in  the  hollow  gun 
the  great  object  of  my  improvement  was  in  part,  if  not  fully,  attained, 
viz.,  to  throw  the  gun  upon  a  strain,  such,  that  under  the  action  of  the 
law  of  strain,  as  stated  above,  each  one  of  the  infinitely  thin  cylinders 
composing  the  thickness  of  the  gun  shall  be  brought  to  the  breaking- 
strain  at  the  same  instant.  This  condition  would  give  us  for  the  effective 
resistance  to  rupture  in  a  gun  one  .(1)  calibre  thick,  2#,  instead  of  fa — 
which  has  been  shown  to  be  all  that  could  be  obtained  from  a  gun  free 
from  strain  by  cooling — and  is,  doubtless,  much  more  than  can  possibly 
be  attained  in  practice.  The  higher  the  metal,  and  the  greater  its  con- 
traction in  cooling,  and  the  more  rapidly  the  gun  is  cooled,  the  further 
will  the  solid  one  fall  below  §a,  and  the  more  nearly  will  the  hollow  one 
approach  2a,  provided  the  cooling  be  effected  from  the  interior ;  also,  the 
greater  the  diameter  of  the  solid  gun,  the  greater  will  be  the  strain  from 
cooling.  It  is  not  considered  practicable  to  cool  a  gun  so  rapidly  from 
the  interior  as  to  cause  rupture  to  commence  on  the  exterior. 

Extract  from  the  report  of  the  Joint  Committee  on  the  Conduct  of  the  War. 

The  Dahlgren  gun  is  the  invention  of  Eear- Admiral  John  A.  Dahlgren, 
and  is  distinguished  by  its  exterior  form.  The  plan  adopted  to  avoid  the 
strain  consequent  upon  cooling  a  solid  casting  of  large  size  from  the  out- 
side is  to  make  the  casting  considerably  larger  than  would  otherwise  be 
needed  to  produce  a  gun  of  the  required  size,  anneal  it  after  cooling,  and 
then  turn  it  down  to  the  proper  size  and  form.  But  the  Dahlgren  guns 
of  the  largest  calibre  are  now  being  manufactured  upon  the  Eodman 
principle. 

The  Rodman  gun,  while  having  to  some  extent  its  peculiarity  of  form, 
is  principally  distinguished  by  the  mode  adopted  in  its  manufacture, 
which  is  an  invention  of  Major  T.  J.  Eodman.  The  casting  is  made 
around  a  hollow  core,  or  core-barrel,  as  it  is  termed,  into  which  is  intro- 
duced a  stream  of  cold  water,  the  outside  of  the  casting  being  kept  heated 
until  the  cooling  from  the  interior  reaches  the  outer  portion  of  the  mass 
of  metal  forming  the  casting.  This  mode  of  manufacture,  it  is  claimed,, 
insures  two  important  advantages  over  the  old  method  of  casting  the 
gun  solid  and  then  boring  it  out.  The  strain  upon  the  metal  produced 
by  cooling  in  large  masses  is  reversed,  rendering  the  gun  less  liable  to 
burst  from  the  explosion  of  the  powder  in  it ;  and  a  much  greater  degree 
of  hardness  is  given  to  the  interior  surface,  rendering  the  gun  less  liable 
to  abrasion  in  the  bore  by  the  passage  of  the  projectile  along  it  and  the 
action  of  the  gases ^of  the  powder  upon  the  metal.  It  is  generally  held 
by  the  witnesses  ,that  no  effective  gun  of  large  calibre  can  be  made  of 
cast  iron  except  upon  the  Eodman  principle,  or  the  principle  of  cooling 
from  the  interior. 


176          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Extracts  from  Mallet  on  Artillery. 

SEC.  32.  A  certain  amount  of  contraction  on  becoming  solid  from  the 
liquid  state  occurs  in  all  castings.  It  is  well  known  to  practical  found- 
ers that  for  cast  iron  this  is  variable,  and  depends  upon  the  mass  of  the 
casting,  being  greatest  for  small  and  least  for  large  castings  of  the  same 
"make"  of  iron;  but  it  is  obvious,  and  it  follows  from  Mr.  Bolley's 
researches,  that  the  contraction  also  will  be  greater  in  proportion  as  the 
metal'  is  poured  into  the  mould  at  a  higher  temperature,  although,  from 
the  expansion  in  the  act  of  crystallizing,  the  specific  gravity  of  the  solid 
mass  maybe  less  at  the  higher  than  at  the  lower  temperature  of"  pouring.7" 

SEC.  33.  As,  therefore,  there  are  two  conditions  that  principally  affect 
the  degree  of  contraction — the  total  change  of  volume  between  the  liquid 
metal  and  its  solid  casting,  namely,  the  extent  to  which  the  fluid  metal 
as  entering  the  mould  has  been  expanded  by  elevation  of  temperature 
and  the  state  of  final  aggregation  of  the  crystalline  particles,  which  we 
have  seen  depends  much  upon  the  former — so  there  will  be  a  determinate 
amount  of  contraction  due  to  a  determinate  thickness  or  mass  of  casting, 
irrespective  of,  though  "also  related  to,  the  co-efficient  of  contraction  for 
any  particular  "make"  of  iron;  for  there  is  no  doubt  that  different 
makes,  cceteris  paribusj  contract  somewhat  differently.  From  whenc.e  it 
follows  that  different  parts  of  the  same  casting,  if  differing  materially 
in  scantling  or  mass,  will  have  different  amounts  of  final  contraction. 

SEC.  34.  Sudden  changes  of  form  or  of  dimensions  in  the  parts  of 
cast-iron  guns,  besides  the  injury  they  do  to  the  crystalline  structure  of 
the  mass,  introduce  violent  strains,  due  to  the  unequal  contraction  of 
the  adjoining  parts,  whose  final  contraction  has  been  different. 

How  desirable  is  it,  therefore^  to  introduce  such  alterations  of  the 
forms  of  our  ordnance  as  shall  avoid  those  sudden  and  enormous  (and 
often  useless)  changes  of  adjacent  mass,  that  we  observe;  as  for  example, 
in  the  sea  and  land  service  13-inch  mortars,  where  at  the  chamber  (where 
the  strain  being  as  D  is  least)  the  thickness  of  metal  suddenly  approaches 
twice  that  of  the  chase — a  malconstruction  the  full  evils  of  which  we 
have  yet  to  consider. 

SEC.  35.  The  amount  of  lineal  contraction  due  to  solidification  of  cast- 
iron,  appears  to  vary  with  metal  and  circumstances  of  casting,  from  Tis 
up  to  gL  of  the  dimensions  of  the  cold  mass.  Its  contraction  in  volume, 
therefore,  (more  than  three  times  this,)  and  probably  not  equal  in  the 
directions  of  three  rectangular  axes,  owing  to  the  christalline  struc- 
ture, is  so  great,  and  the  difference  such,  between  its  measure  for  large 
and  small  parts  of  the  same  casting,  that  the  latter  never  should  be 
neglected. 

SEC.  43.  Besides  the  effects  already  referred  to,  due  to  the  contrac- 
tion of  cast-iron  in  becoming  solid,  another  class  of  abnormal  strains 
introduced  by  the  consolidation  of  one  portion  of  a  casting  before  another 
must  not  be  passed  over,  as  often  producing  results  of  the  most  import- 
ant character  in  artillery.  This  will  be  more  readily  understood  by 
immediate  reference  to  example.  When  a  large  gun,  or,  still  more,  a 
large  mortar,  is  cast  solid,  and  the  metal  cools  in  the  ordinary  way,  the 
external  portions  solidify  long  before  the  interior  has  ceased  to  be  liquid, 
and  the  process  of  solidification  is  propagated,  as  it  were,  in  parallel 
"couches"  from  the  outside  to  the  centre  of  the  mass.  The  lineal  con- 
traction of  any  one  couch  assumed  of  indefinite  thickness  is  in  the 
direction  of  its  circumference  directly  proportionate  to  that  circumfer- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  177 

ence;  and  so  it  would  seem  (at  first)  that  the  contraction  of  the  whole 
assemblage  should  be  at  every  point  proportionate  to  its  distance  from 
the  centre,  and  that  so  the  solid  when  all  cold,  should  be  left  in  a  state 
of  molecular  equilibrium.  This  is  not  the  case,  however,  for  no  sooner 
has  the  first  couch  or  thickness  of  solid  crust  formed  on  the  exterior, 
than  it  forms  a  complete  arch  all  around,  so  that  the  contraction  between 
fluidity  and  solidification  of  each  subsequent  couch  is  accommodated 
(the  continuity  of  the  mass  remaining  unbroken  throughout)  by  portions 
of  matter  withdrawn  radially  from  the  interior  toward  the  still  cooling 
exterior;  that  is  to  say,  from  a  smaller  towards  a  larger  circumference. 
SEC.  53.  Unequal  cooling,  especially  if  very  rapid,  involves  all  the 
injury  that  violent  internal  wrenching  and  straining  can  do  to  strength, 
strains  of  the  very  same  character  as  those  under  which  it  is  part  of  the 
purpose  of  this  paper  to  show,  that  guns  burst,  and  which  often,  in 
the  every  day  practice  of  the  iron-founder,  result  in  actual  fracture. 

Extract  from  the  testimony  of  Brigadier  General  George  D.Ramsey  Before 
the  Joint  Committee  on  the  Conduct  of  tlie  War. 

Q.  In  what  does  the  patent  consist  in  this  Eodman  gun  for  which  this 
royalty  is  paid  by  the  government  to  Mr.  Knap  ;  and  in  what  does  the 
difference  consist  between  that  gun  and  guns  cast  in  the  common  or 
ordinary  mode  ? 

A.  Heretofore  all  cannon  were  cast  solid  and  allowed  to  cool  in  the 
casting  pit.  In  this  way  the  cooling  of  the  fluid  metal  from  the  exterior 
extended  gradually  towards  the  inside,  which  was  the  last  part  that 
solidified.  The  shrinkage  by  this  mode  of  cooling  tended  to  separate 
the  interior  layers  of  metal  from  the  exterior.  In  Hodman's  plan,  the 
patent  consists  of  cooling  from  the  interior  and  keeping  the  outside  hot; 
the  shrinkage  begins  on  the  inside  of  the  mass,  and  each  layer  of  metal 
as  it  cools  shrinks  upon  the  nearest  interior  layer,  thus  binding  all  the 
successive  layers  together. 

Extract  from  Ordnance  and  Armor,  "  Holly?  p.  234. 

278.  I.  Increasing  the  thickness  of  the  walls. — The  most  obvious  means, 
of  enabling  any  vessel  to  sustain  a  greater  elastic  pressure,  such  as  the 
gas  of  exploded  gunpowder,  is  to  simply  thicken  its  sides,  thus  increasing 
the  area  of  substance  to  be  torn  asunder.    This  rule  is  founded  upon  the 
practical  facts  of  every-day  engineering,  which  usually  deal  with  com- 
paratively low  pressures  and  thin  walls.    Even  in  case  of  guns  of  small 
calibre  it  has  proved  tolerably  safe.    But  when  these  conditions  are 
greatly  changed — when  the  problem  is,  for  instance,  to  throw  projectiles 
of  13  to  15  inches  diameter  at  the  rate  of  1,500  to  1,800  feet  per  second, 
and  the  gun  is  proportionally  thickened  to  stand  the  excessive  strain  due 
to  both  the  increased  pressure  per  square  inch  and  the  increased  num- 
ber of  square  inches  pressed  upon,  another  law,  unobserved  in  ordinary 
practice,  assumes  a  very  serious  importance.    This  law  is  thus  clearly 
explained  by  Captain  Blakely :  * 

279.  To  obtain  much  greater  strength  by  casting  guns  heavier  is 
impossible,  because  in  cast  guns  (whether  of  iron,  brass,   or  other 
metal,)  the  outside  helps  but  very  little  in  restraining  the  explosive 
force  of  the  powder  tending  to  burst  the  gun,  the  strain  not  being  com- 
municated to  it  by  the  that  intervening  metal.     The  consequence  is  in 
large  guns  the  inside  is  split,  while  the  outside  is  scarcely  strained. 
This  split  rapidly  increases,  and  the  gun  ultimately  bursts. 

This  will  be  more  easily  understood  by  considering  the  case  of  a 
much  more  elastic  tube;  for  instance,  an  India-rubber  cylinder,  10 
inches  in  internal  diameter  and  10  inches  thick,  therefore  30  inches 
in  external  diameter.  Such  a  cylinder  might  be  strained  by  pressure 

*  A  Cheap  and  Simple  Method  of  Manufacturing  Cannon,.  1858. 

Eep.  No.  266 12 


178 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


Fig.  131. 


Fig.  132. 


from  within  till  the  inside  stretched  to  double  its  original  circumference.     The  diameter 
would,  of  course,  also  be  doubled,  and  would  be  20  inches  instead  of  10. 

Now  it  is  evident  that  the  outside  circumference  and  diameter  cannot  be  doubled  at  the 
Fig.  130.  same  time,  or  else  the  latter  must  become  twice  30  or  60  inches 

which  would  give  a  thickness  of  20  inches,  quadrupling  the  mass 
of  material,  which  is  impossible.  A  moment's  reflection  shows 
that  the  thickness  must  diminish  as  the  circumference  is  increased 
by  pressure  from  within,  for  if  the  thickness  remain  10  inches 
when  the  internal  diameter  has  become  20,  the  external  diameter 
must  be  20  plus  twice  10,  or  40  inches.  This  could  not  be  unless 
we  imagine  wrhat  seems  impossible,  viz,  that  the  bulks  of  the 
material  is  considerably  enlarged,  as  each  inch  in  length  of  the 
cylinder  would  now  contain  1,200  cylindrical  inches,  (the  differ- 
ence between  the  squares  of  40  and  20,  the  external  and  internal 
diameters,)  whereas,  originally,  it  only  contained  800 inches,  the 
difference  between  the  squares  of  30  and  10. 

Yet,  even  if  the  thickness  could  remain  the  same,  notwithstand- 
ing the  increase  of  circumference,  the  outside  layer  could  only  be 
strained  one-third  as  much  as  the  inside  one,  because  three  times  as 
long.  The  same  elongation,  which  wrould  cause  a  strain  of  one 
ounce  or  one  pound  in  the  longer  circumference,  would  cause  a 
strain  of  three  ounces  or  three  pounds  in  the  shorter  one,  and  the 
elongation  which  would  but  moderately  strain  the  one  would  break 
the  other.  This  reasoning  is  equally  applicable  to  the  minute 
extension  of  iron ;  the  increase  of  one-tenth  of  an  inch  in  the  outer 
circumference  of  a  10-inch  gun  being  possible  without  fracturing 
that  part,  being  an  elongation  of  but  one  in  940 ;  whereas  the  same 
extension  must  crack  the  inside,  as  no  iron  could  stand  an  elon- 
gation of  one-tenth  in  31^,  or  one  in  314. 

Even  on  this  showing,  then,  the  outside  of  a  thick  tube  cannot 
do  its  share  of  work ;  a  closer  examination,  however,  must  con- 
vince us  that  this  is  an  over-estimate  of  it,  for  the  thickness  of  mate- 
rial must  diminish  as  the  circumference  is  increased.  When  the  inner 
diameter  of  the  10-inch  cylinder  becomes  20  inches,  the  thickness  must 
diminish  from  10  to  7.32  inches,  the  cross-section  of  the  cylinder 
remaining  the  same.  This  cross-section  was  originally  800  circular 
inches,  800  being  the  difference  between  the  squares  of  30  inches, 
the  inner,  or  900  minus  100.  When  stretched  the  area  of  the  cross- 
section  must  continue  to  be  800  round  inches.  Now  a  thickness  of 
7.32  inches  gives  us  an  external  diameter  of  twice  7.32  or  14.64 
added  to  20,  the  internal  diameter,  in  all  34.64  inches,  the  square 
of  which  is  1,200.  Subtracting  400,  the  square  of  20  leaves  800 
round  inches  as  before.  In  this  case  the  outside  of  the  cylinder  is 
stretched  but  4.64  in  30,  about  one  in  seven,  when  the  inside  is 
stretched  to  double  its  original  size.  If  the  inner  diameter  be  only 
stretched  to  11  inches  the  thickness  must  be  diminished  from  10 
to  9.674  inches,  the  outer  diameter  becoming  30.348  inches,  the 
cross-section  remaining  800  round  inches,  as  before,  the  difference 
between  the  squares  30.348  and  11.  Here  the  outer  layer  is  elon- 
gated .348  in  30,  or  1  in  86;  whereas  the  inner  is  extended  1  in  10, 
showing  a  strain  or  an  exertion  of  power  8£  times  greater. 

In  the  minute  extension  of  metals  the  disproportion  is  still  more 
striking.  Thus  in  cast-iron  the  10-inch  inner  diameter  may  become 
1  OTCRJ?  which  would  extend  the  outer  diameter  only  from  30  to  30^^, 
the  cross-section  remaining  800  inches,  and  the  thickness  dimin- 
ishing from  10  inches  to  9|t)o.  Here  the  outside  would  only  be 
stretched  ^^  in  30,  or  1  in  9,000,  the  inside  being  stretched  yjj^ 
in  10,  or  1  in  1,000,  exerting,  therefore,  nine  times  as  much  power 
a?  the  outside.  It  is  evident  that  a  slight  increase  of  pressure 
from  within  would  break  the  inside,  while  the  outside  could  help  but 
little  in  restraining  the  disruptive  force. 

280.    If  we  make  equidistant  circular  marks  on  the  end  of  an 
India-rubber  cylinder,    (Fig.    134,)  and  stretch  it,  we  can   see 
plainly  how  much  more  the  inside  is  strained  than  the  outside 
India-rubber  cylinder,  with    or  cven  the  intermediate  parts.     The  spaces  between  the  marks 
equidistant  concentric  marks,   will  become  thinner,  each  space  becoming  less  thin  than  that  inside 


Fig.  133. 


EXPERIMENTS    ON   HEAVY    ORDNANCE. 


179 


The  same  cylinder  stretched  by 


Fig.  136. 


Cylinder  burst  by  internal  pres- 


of  it,  but  the  inner  space  much  thinner  than  the  other?,  (see  Fig.  135. 

Fig  135,)  showing  that  when  the  inside  is  strained  almost  to 
breaking,  the  intermediate  parts  are  doing  much  less  work, 
and  those  far  removed  almost  none. 

281.  Law  of  strength  of  cylinders.  —  In  the  first  volume  of  the 
"Transactions"  of  the  Institute  of  Civil  Engineers,  p.  133, 
there  is  a  naper  by  Professor  Peter  Barlow,  F.  R.  S.,  on  the 
Strength  of  Cylinders.     The   law   he   deduces   is,    that    "in 
cylinders  of  metal  the  power  exerted  by  different  parts  varies 
inversely  as  the  squares  of  the  distances  of  the  parts  from  the  axis." 
Thus,  in  a  10-inch  gun,  when  the  inside,  which  is  five  inches 
from  the  axis,  is  fully  strained,  the  metal  two  inches  from  the 
inside,  or  seven  inches  from  the  axis,  can  only  exert  a  force  f  f  , 
or  little  more  than  half  as  much  ;  three  inches  further,  ten  inches^ 
from  the  axis,  the  force  exerted  diminishes  to  £&,  or  but  a 
Barter  of  that  exerted  by  the  inside  ;  and  if  the  gu£  be  twelve 

inches  thick,  the  outside,  which  is  seventeen  inches  from  the  of  the  exterior. 

axis,  can  exert  but  ^9,  or  about  ^  as  much   power   as    the 

inside.     Of  course,  casting  the  gun  still  thicker  would  add  but 

very  little  to  its  strength  ;  we  cannot,  therefore,  be  astonished 

that  it  has  been  found  in  practice  that  cylinders  for  hydraulic 

presses,  with  a  thickness  equal  to  about  one-half  the  diameter 

of  the  piston,  are  very  nearly  as  strong  as  if  ten  times  as  thick. 

282.  In  1855,  Dr.  Hart,  of  Trinity  College,  Dublin,  investi- 
gated the  problem.     His  calculations  (see  note  W,  p.  259,  of 
Mr.  R.  Mallet's  work  on  the  Construction  of  Artillery)  give 
greater  strength  to  the  inner  parts,  but  still  less  to  the  outer,  than 
those  of  Professor  Barlow.     Both  these  gentlemen,  as  well  as 
General  Morin,  and  Dr.  Robinson,  the  astronomer,  who  have 
also  studied  the  question,  agree  that  no  possible  thickness  can 
enable  a  cylinder  to  bear  a  pressure  from  within  greater  on  each 
square  inch  than  the  tensile  strength  of  a  square  inch  bar  of  the 
materiul;  that  is  to  say,  if  the  tensile  strength  of  cast-iron  be  sure. 
six  tons  per  inch,  a  cylinder  of  that  metal,  however  thick,  cannot 
bear  a  pressure  from  within  of  six  tons  per  inch. 

283.  The  report  of  experiments  made  by  the  United  States  govern- 
ment in  bursting  hollow  cylinders  by  internal  pressure  states  that  "the 
general  range  of  the  results  appears  to  sustain  Mr.  Barlow's  hypothesis.7'* 

284.  In  further  proof  of  the  foregoing  facts.  Captain  Blakely  cites  the 
actual  fracture  of  some  cylinders  (Fig.  136)  made  by  Mr.  Longridge,  of 
iron  wound  with  wire.    The  cracks  were  u  much  more  open  at  the  inside, 
and  some  not  extending  to  the  outside." 

285.  The  law  of  diminution  in  the  power  of  resistance  is  also  illustrated 
by  Professor  Treadwell,  who  states  it  as  follows  :t 

Suppose  such  a  cylinder  to  be  made  up  of  a  great  number  of  thin  rings  or  hoops,  placed 
one  within  another.  Then  the  resistance  of  these  rings,  compared  one  with  another,  to  any 
distending  force,  will  be  inversely  as  the  squares  of  their  diameters.  If  we  make  a  cylin- 
der of  4  1  concentric  hoops  of  equal  thickness,  disposed  one  within  another,  and  exactly  fitting, 
so  that  the  particles  of  each  hoop  shall  be  in  equilibrium  with  each  other,  the  diameter  of  the 
largest  being  five  times  that  of  the  smallest,  then  the  force  of  each,  beginning  with  the  inner- 
most, to  resist  distension,  will  be  represented  by  the  following  numbers  : 

1000  ........  444  ........  250  ........  160  .........  Ill  .........  82  .........  62  .........  49 

826  ........  391  ........  225  ........  148  .........  104  .........  77  .........  59  .........  47 

694  ........  346  ........  207  ........  137  .........  98  .........  73  .........  56  .........  45 

591  ........  309  ........  189  ........  128  .........   92  .........  69  .........  54  .........  43 

510  ........  277  ........  174  ........  119  ........  .  87  .........  65  .........  51  .........  41 

.........  40 

An  inspection  of  these  numbers  must,  I  think,  impress  any  one  with  the  fact  that  it  is 
impossible  to  increase  essentially  the  strength  of  cannon  by  a  simple  increase  of  thickness. 

286.  The  weakness  of  a  homogeneous  cylinder,  and  the  remedy,  (which 
will  be  considered  in  the  following  article,)  have  been  mathematically 
investigated,  with  great  care,  by  Dr.  Hart,  of  Trinity  College,  Dublin, 


*  Reports  of  Experiments  on  Metals  for  Cannon ;  1856. 

t  "The  Practicability  of  Constructing  Cannon  of  Great  Calibre,' 


&c. ;  1856. 


180 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


and  Mr.  C.  H.  Brooks,  from  whose  calculations  it  has  been  illustrated  and 
made  the  subject  of  a  paper  by  Mr.  James  Atkinson  Longridge,  followed 
by  an  important  discussion  before  the  Institution  of  Civil  Engineers. 
Mr.  Longridge  says:* 

If,  in  Fig.  137,  A  B  C  D  represent  a  portion  of  a  section  of  an  8-inch  gun,  of  which  A  G  B 
is  the  inner,  and  D  F  C  the  outer  circumference,  the  state  of  tension  of  any  particle  between 
G  and  F  may  be  denoted  by  ordinates  drawn  at  the  points  in  question,  those  above  G  F 
representing  tension,  and  those  below  compression. 

If  now  the  gun  be  of  any  homogeneous  material,  such  as  cast-iron,  the  state  of  tension  at 
the  time  of  explosion,  and  when  the  gun  is  about  to  burst,  will  be  denoted  by  a  curve  H  I. 

Fig.  137. 


Hlustrating  a  strain  on  a  homogeneous  gun. 

or  II  i,  the  former  calculated  according  to  Professor  Hart,  and  the  latter  according  to  Pro- 
fessor Barlow's  formula.  Then,  supposing  the  tensile  force  of  the  material  to  be  12  tons  per 
square  inch,  and  the  thickness  of  the  gun  64-  inches,  when  the  strain  at  G  is  G  H,  or  12  tons, 
at  F  it  is  F  1  =  3  tons,  or  F  i==  If  tons,  according  as  the  one  or  other  formula  is  adopted. 
The  areas  of  these  curves  give  the  total  strengths  of  the  gun  at  the  bursting  point,  and  are 
found  to  be  36.72  tons  and  30.871  tons  respectively,  instead  of  78  tons,  which  it  would  have 
been  if  uniformly  strained  at  12  tons  per  square  inch. 

287.  II.  Hoops  with  initial  tension  to  resist  elastic  pressure. — This  sys- 
tem consists  in  making  a  gun  of  concentric  tubes  by  putting  on  each 
successive  layer,  proceeding  outward  from  the  centre,  with  an  initial 
tension  exceeding  that  of  those  below  it,  or  so  that  each  hoop  or  tube 
shall  compress  what  is  within  it.  The  inner  layer  is  thus,  in  its  normal 
state,  in  compression,  while  the  outer  layer  is  in  the  highest  tension. 

Then,  by  the  law  illustrated  in  the  foregoing  paragraph,  the  inner 
layer  being  in  compression  is  able  to  sustain  the  first  and  greatest 
stretch,  and  the  outer  layer,  although  stretched  less  by  the  explosion  of 
the  powder,  has  already  been  stretched  into  high  tension,  and  thus  has 
to  do  an  equal  amount  of  work.  The  intermediate  layers  bear  the  same 
relations  to  the  initial  strain  and  the  strain  of  the  powder,  so  that,  in 
short,  all  the  layers  contribute  equally  of  their  tensile  strength  to  resist 
the  strain  of  the  explosion. 

*  "Construction  of  Artillery,"  Inst.  C.  E  ,  1860. 


EXPERIMENTS    ON   HEAVY    ORDNANCE.  181 

ON  LARGE  CAST-IRON  GUNS. 

From  tJie  Army  and  Navy  Journal. 

The  interest  awakened  by  the  previous  extracts  we  have  made  from 
the  advance  sheets  of  General  Gillmore's  report  induces  us  to  continue 
them  this  week.  We  select  the  generaPs  remarks  on  cast  guns  of  large 
size: 

A  safe  and  advantageous  arrangement  and  distribution  of  the  materials 
of  a  large  cast  gun — particularly  of  a  rifle-gun — to  enable  them  to  sustain 
the  successive  strains  and  shocks  to  which  they  will  be  subject  in  firing, 
is  incompatible  with  the  condition  that  the  gun  shall  be  composed  of  a 
single  piece  of  homogeneous  nietal.  With  forged  guns  of  good  wrought 
iron,  like  that  from  Salisbury,  Connecticut,  the  case  is  somewhat  different, 
particularly  if  the  workmanship  be  such  that  the  piece  will  not  first  give 
way  at  the  welds.  The  greatest  tensile  strength  and  ductility  of  the 
metal  are  both  brought  into  action.  In  firing,  the  bore  of  the  gun  rap- 
idly receives  a  permanent  enlargement,  within  the  limit  of  rupture.  The 
surrounding  metal  is  thus  placed  under  tension,  and  the  piece  strength- 
ened to  a  certain  extent.  The  further  stretching  of  the  bore,  beyond 
the  power  of  the  metal  to  bear,  is  thereby  prevented.  In  a  wrought-iron 
gun  there  is  very  little  enlargement  of  the  bore  after  the  first  fifty  rounds, 
if  fired  with  heavy  charges.  Such  guns  should  first  be  bored  a  little 
smaller — about  two-tenths  of  an  inch — than  they  are  required  to  be,  and 
should  then  be  fired  with  a  few  large  charges,  and  re-bored  to  the  proper 
calibre. 

The  forces  which  act  upon  a  gun,  tending  to  destroy  it,  are  due  prin- 
cipally to  the  explosive  force  of  the  powder,  and  the  expansion  of  the 
gun  by  heat. 

In  smooth-bore  guns,  the  maximum  force  of  the  powder — or,  in  other 
words,  the  maximum  pressure  blowing  out  in  front  of  the  reinforce — was 
in  consequence  of  the  inadequate  length  of  the  latter. 

It  is  known,  from  repeated  experiments,  that  the  distending  strain 
upoD  the  metal  of  a  gun,  at  points  equally  distant  from  the  muzzle — 
that  is,  within  the  same  transverse  circular  section — varies  inversely 
with  the  squares  of  the  distances  of  those  points  from  the  axis  of  the 
bore.  Thus,  at  five  inches  from  the  axis,  the  strain  upon  the  metal  would 
be  about  double  what  it  would  be  at  the  distance  of  seven  inches,  or  in 
the  ratio  of  49  to  25. 

If  we  suppose  a  cylinder  to  be  made  up  of  a  great  number  of  very  thin 
concentric  cylinders,  in  a  condition  of  initial  molecular  repose,  then  the 
strain  upon  these  several  cylinders,  due  to  any  distending  force  equally 
distributed  over  the  inner  surface  of  the  inner  one,  would  vary  inversely 
with  the  squares  of  their  diameters. 

Professor  Treadwell  illustrates  this  law  of  diminution  in  the  following 
manner: 

"If  we  make  a  cylinder  of  41  concentric  hoops  of  equal  thickness, 
disposed  one  within  "another,  and  exactly  fitting,  so  that  the  particles  of 
each  hoop  shall  be  in  equilibrium  with  each  other,  the  diameter  of  the 
largest  being  five  times  that  of  the  smallest,  then  the  force  of  each, 
beginning  with  the  innermost,  to  resist  distension,  will  be  represented 
by  the  following  numbers : 

1000 444 250 160 Ill 82. 62 49 

826 391 225 148 104 77 59 47 

694 346 207 137 98 73 56 43 

591 309 189 128 92 69 54 45 

510 277 174 119 87 65 51 41 

...40 


182          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

There  is  another  important  fact  deduced  by  mathematical  calculation, 
and  sustained  by  experiments  in  both  this  country  and  Europe,  viz: 
that  no  increase  of  thickness,  however  great,  can  enable  a  homogeneous 
cylinder  to  sustain  a  distending  pressure  from  within,  on  each  square  inch, 
exceeding  the  tensile  strength  of  a  bar  of  the  material  one  inch  square. 

Hence  it  is  useless  to  attempt  to  augment  the  strength  of  a  gun  by 
increasing  its  thickness  beyond  a  certain  point,  "  because,"  as  Captain 
Blakely  remarks,  "in  cast  guns  (whether  of  iron,  brass,  or  other  metal) 
the  outside  helps  very  little  in  restraining  the  explosive  force  of  the 
powder  tending  to  burst  the  gun,  the  strain  not  being  communicated  to 
it  by  the  intervening  metal.  The  consequence  is  that,  in  large  guns, 
the  inside  is  split  ivhile  the  outside  is  scarcely  strained.  This  split  rapidly 
increases,  and  the  gun  ultimately  bursts." 

In  other  words,  the  exterior  part  of  a  homogeneous  gun  gives  way  to 
forces  applied  by  wedging  and  leverage,  and  not  to  a  transmitted  tensile 
strain. 

We  see,  therefore,  how  inadequately  the  hooping  of  old  and  nearly 
expended  guns  accomplishes  the  object  in  view,  of  conferring  upon 
them  additional  powers  of  endurance,  since  the  exterior  hoop  simply 
reinforces  metal  that  has  not  only  never  had  its  strength  impaired  by 
use,  but  is  not  liable  to  be  brought  under  any  strain  exceeding  that 
which  it  is  well  able  to  bear,  except  a  splitting  from  the  inside,  which  a 
hoop  can  but  feebly  if  at  all  restrain. 

The  only  apparently  effective  way  to  utilize  the  strength  of  the  exterior, 
unimpaired  metal  of  a  cast  gun  in  which  cracks  have  already  appeared 
on  the  inside,  is  to  replace  a  portion  of  the  inside  metal,  throughout  the 
entire  length  of  the  bore,  by  a  tube  of  tough  and  elastic  material,  placed 
under  slight  compression  by  cooling  the  gun  upon  it. 

Initial  tension. — We  would  conclude  from  the  foregoing  that  if  a  gun 
be  compounded  of  several  thin  concentric  hoops,  or  cylinders,  those  on 
the  exterior  being  under  suitable  initial  tension,  increasing  according  to 
a  fixed  law  with  their  several  distances  from  the  common  axis,  so  that 
the  aggregate  of  the  initial  tension  and  transmitted  strain,  per  square 
inch  on  each  cylinder,  would  be  just  equal  to  the  tensile  strength  per 
square  inch  bar  of  the  metal,  we  would  obtain  a  combination  satisfying 
the  requisite  conditions  of  maximum  strength  against  statical  pressure ; 
for  a  distending  force  which  would  rupture  the  inner  cylinder  would 
rupture  all  the  others  at  the  same  moment.  The  greater  the  number  of 
cylinders,  their  aggregate  thickness  remaining  constant,  the  greater 
would  be  the  strength  of  the  combination. 

Varying  elasticity. — Let  us  take  another  view  of  the  case.  If  the 
several  thin  cylinders  be  composed  of  metal  possessing  different  degrees 
of  elasticity,  decreasing  according  to  a  fixed  law  from  the  interior  toward 
the  exterior,  so  that  those  on  the  inside  would,  by  their  greater  elastic 
expansion,  transmit  externally  a  distending  strain  of  such  intensity  that 
the  metal  of  the  several  cylinders  would  reach  the  limit  of  elasticity  at 
the  same  moment,  we  would  then  have  a  combination  of  maximum  stat- 
ical strength,  so  long  as  the  strain  was  not  great  enough  to  give  the 
metal  a  permanent  set;  that  is,  so  long  as  the  elastic  limit  was  not 
exceeded.  When  that  point  is  reached,  the  advantages  of  varying  elas- 
ticity partially  disappeared,  and  are  replaced,  in  a  measure,  by  those 
of  varying  tension. 

A  cannon  compounded  of  many  concentric  cylinders,  combined  on 
either  of  the  foregoing  principles  of  initial  tension  or  varying  elasticity, 
although  possessing  great  theoretical  strength,  and  although  capable  in 
practice  of  sustaining  great  statical  pressure  from  within,  (great,  indeed, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.   .       183 

in  proportion  to  the  number  of  cylinders  used  for  a  given  aggregate 
thickness,)  does  not  possess  sufficient  unity  of  form  to  withstand  the 
repeated  shocks  of  firing.  While  there  must  be,  in  some  degree,  a 
division  of  parts,  in  order  that  the  conditions  necessary  to  resist  statical 
pressure  may  be  imposed  to  a  certain  extent,  there  must  also  exist  in 
cannon  the  requisite  continuity  of  mass  and  structure  to  resist  the 
instantaneous  wave  of  force  and  other  vibrations  created  in  firing. 
Cannon  are  seldom  constructed  of  as  many  as  four  cylinders  ;  generally  of 
not  more  than  two  of  three. 

Captain  Blakely  has  attempted  to  combine  the  distinct  advantages 
of  varying  elasticity  and  initial  tension  by  using  three  tubes.  The  two 
inner  tubes  are  of  steel,  that  possessing  the  greatest  elasticity  forming 
the  bore,  while  the  outer  tube  is  of  cast  iron,  on  which  the  trunnions  are 
cast.  The  tubes  are  shrank  together,  so  that  the  outer  one  is  under 
slight  initial  tension.  The  elastic  limit  of  the  inner  steel  is  thus  favored 
by  bringing  it  under  slight  compression.  Even  should  the  steel  tubes 
become  permanently  strained,  the  gun,  if  properly  constructed,  would 
not  be  weakened  thereby,  as  the  effect  would  be  simply  to  increase  the 
tension  upon  the  cast-iron  jacket.  Captain  Palliser  makes  use  of  this 
principlejin  bringing  his  large  guns  under  suitable  tension  on  the  exterior. 
He  makes  the  inner  tubes  of  soft  metal,  the  most  ductile  one  containing 
the  bore,  and  then  fires  the  gun  with  a  charge  that  will  permanently 
stretch  the  inside.  The  gun  is  then  finished  by  re-boring  to  the  proper 
calibre.  Of  course  the  exterior  cylinder  is  thus  placed  under  initial 
tension. 

Major  Eodman,  of  the  ordnance  department,  United  States  army, 
recommends  a  method,  now  extensively  followed,  for  placing  the  metal 
of  cast-iron  guns  under  the  proper  conditions  of  initial  tension,  by  cast- 
ing them  hollow  and  cooling  them  from  the  inside ;  a  process  which  is 
inapplicable  to  steel  guns,  which  have  to  undergo  annealing. 

In  1856  Professor  Treadwell  proposed  a  method  of  "constructing  can- 
non of  a  large  calibre,"  of  several  tubes,  the  inner  one,  containing  the 
breech,  being  of  cast  iron  about  half  a  calibre  in  thickness.  Upon  this 
he  placed  "rings  or  hoops  of  wrought  iron,  in  one,  two,  or  more  layers," 
by  screwing  them  on.  For  that  purpose  a  screw  or  thread  was  cut  upon 
the  exterior  of  the  inner  or  cast-iron  tube,  and  upon  the  interior  and 
exterior  of  the  other  tubeSj  except  the  outside  of  the  outer  one.  The 
hoops  are  about  one-thousandth  part  of  their  diameter  less  than  the 
parts  they  envelop,  and  are  screwed  to  their  places  while  hot,  to  secure 
the  proper  tension. 

Whether  the  tubes  of  a  compound  gun  should  be  put  together  on 
Professor  Treadwell's  plan,  with  screws,  or  whether  a  more  simple  and 
less  expensive  method  of  combination  will  .give  the  requisite  unity  of 
form,  is  still  a  question  of  discussion.  For  reasons  which  will  not  be 
given  here,  it  is  believed  that  screws  are  unnecessary,  especially  if  the 
trunnions  are  placed  upon  the  outer  tube,  as  in  the  Blakely  and  Whit- 
worth  guns. 

Uffects  of  heat. — The  heat  generated  by  the  burning  charge  induces 
or  increases  compression  on  the  inside  and  tension  on  the  outside  of  a 
gun;  and  therefore,  within  certain  undefined  limits,  strengthens  the 
piece  against  a  distending  strain.  Another  kind  of  strain  is  brought 
upon  the  exterior  of  the  gun  by  the  expansion  of  the  bore  longitudinally. 
Against  this,  a  gun  composed  of  two  or  more  tubes  can  accommodate 
itself  with  less  danger  of  injury  to  the  exterior  than  if  made  from  a  single 
piece  of  metal,  for  the  interior  tube,  instead  of  forcing  the  exterior  to 
elongate  with  it,  or  yield  to  rupture,  slips  through  it. 


184          EXPERIMENTS  ON  HEAVY  QRDNANCE. 

The  composition  of  the  armament  of  land  batteries  for  channel  defence, 
in  the  present  condition  of  the  great  question  of  ships  against  forts, 
should,  of  course,  have  special  reference  to  the  defence  against  armored 
vessels.  The  best  proportion  for  the  two  kinds,  rifles  and  smooth-bores, 
the  most  advantageous  calibre  for  smooth-bores,  whether  large  or  medium 
size,  or  a  mixture  of  both,  are  questions  upon  which  a  diversity  of  opinions 
exist  among  military  and  naval  men.  The  invention  of  a  large  gun  of 
12  or  15  inch  calibre  sufficiently  strong  to  be  used  effectively  as  a  rifle, 
and  rifled  in  such  a  manner  as  would  not  impair  its  qualities  as  a  smooth- 
bore, would  be  a  great  advance  in  artillery.  With  such  a  gun  heavy 
elongated  projectiles  would  be  used  with  comparatively  low  velocities, 
at  either  long  or  short  range,  for  their  smashing  effect  upon  armor,  while 
solid  steel  or  cast-iron  spheres,  and  bolts  and  long  percussion  shells  at 
high  velocities,  would  be  very  destructive  in  cutting  and  punching 
through  armor,  and  also  upon  the  men  and  guns  and  machinery  inside. 

Batteries  for  channel  and  harbor  defence  should  contain  some — but 
in  what  proportion  I  am  not  prepared  to  suggest — of  the  largest  calibres 
that  can  be  manoBuvred  with  ease  and  rapidity.  For  cutting  through 
unimpaired  armor  at  short  range,  in  order  to  reach  vital  parts  within  as 
quickly  as  possible,  smaller  calibres  are  better,  as  they  will  stand  greater 
relative  charges  and  yield  higher  velocities  safely. 

EFFECT  OF  SIZE  OF  MASS  ON  STRENGTH  AND  TEXTURE  OF  CAST-IRON. 

Extract  from  Mallett  on  Artillery. 

SECTION  24.  It  is  known  to  every  practical  iron-founder  upon  a  large 
scale  that  generally  the  larger  the  mass  of  casting  he  makes  with  any 
given  quality  of  cast  iron  the  "  coarser  is  the  grain?  that  is,  the  larger  are 
the  crystals  that  develop  themselves  in  the  mass. 

SEC.  30.  That  the  lower  the  temperature  at  which  the  fluid  cast  iron 
is  poured  into  the  mould,  and  the  „  more  rapidly  the  mass  can  be  cooled 
down  to  solidification,  the  closer  will  be  the  grain  of  the  metal;  the 
smaller  its  crystals  the  fewer  and  least  injurious  the  "  planes  of  weakness," 
and  the  greater  the  specific  gravity  of  the  casting  cceteris  paribus. 

SEC.  50.  Slow  cooling  develops  a  coarse,  uneven  grain,  with  large  but 
thoroughly  irregular  and  confused  crystallization.  Cast  iron  with  such 
a  grain  is  never  strong  or  cohesive,  though,  perhaps  soft  and  extensible. 
The  more  rapidly  a  casting  once  consolidated  can  be  cooled,  without 
introducing  injurious  effects,  the  finer,  closer,  and  more  even  will  be  its 
grain  on  fracture,  and  with  any  given  metal  the  greater  will  be  its 
strength.  The  rate  of  cooling  cannot  be  accelerated  beyond  a  moderate 
limit.  If  this  limit  be  exceeded,  as  by  casting  in  a  cold,  thick,  highly 
conducting  metallic  mould,  the  iron  is  "chilled,"  its  chemical  or  at  least 
its  mixed  constitution  changed,  and  the  uncombined  graphite  is  exuded, 
the  combined  carbon  only  remaining  in  the  white  chilled  metal.  It  can- 
not be  so  fast  as  to  endanger  unequal  contraction,  nor  must  it  be  so  fast 
in  large  castings,  such  as  guns,  requiring  to  be  afed"  from  a  "  feeding 
head"  with  fresh  portions  of  hot  fluid  metal  during  consolidation  to  fill 
up  the  internal  cavities  or  porosity  due  to  contraction  and  crystallization, 
as  already  explained,  that  this  feeding  cannot  be  accomplished.  The 
prevalent  notion,  however,  that  the  soundest  and  strongest  castings  are 
obtained  by  letting  them  cool  slowly  in  the  moulds  is  founded  on  a  radi- 
cal error. 


EXPERIMENTS    ON   HEAVY    ORDNANCE.  185 


RELATION  OF  SIZE  OF  MASS  TO  STRENGTH  AND  TEXTURE  OF  WROUGHT 

IRON. 

Extract  from  Mallett  on  Artillery. 

SECTION  213.  We  have  found  that  the  effect  of  large  increase  in  the 
mass  of  wrought  iron,  in  connection  with  its  necessary  or  exisitiug  modes 
of  manufacture,  is  to  prevent  by  process  any  regular  or  uniform  arrange- 
ment of  its  integral  crystals;  that  as  such  masses  are  necessarily 
continued  long  heated  while  forging,  occupy  long  in  cooling,  and  con- 
tract considerably  in  all  their  dimensions  in  cooling,  so  the  crystals  are 
developed  to  a  large  size  and  become  arranged  to  a  greater  or  less 
extent  in  directions  transverse  to  the  surfaces  of  external  contour  of 
the  mass. 

The  results  are  irregular  "  planes  of  weakness,"  reduction  of  ultimate 
strength  to  resist  a  quietly  and  steadily  applied  tensile  force  of  from  20 
to  17,  or  in  very  large  masses  of  from  5  to  4  in  round  numbers,  and  reduc- 
tion of  resisting  power  to  such  impulsive  forces  as  are  concerned  with 
artillery  in  the  ratio  of  from  7J  to  1,  or  probably  even  more;  for  a  train 
of  difficulties  are  introduced  in  the  manufacture,  and  of  injuries  done  to 
the  chemical  qualities  of  the  material,  in  proportion  as  we  continue  to 
increase  the  magnitude  of  the  mass  to  be  forged. 

SEC.  214.  When  the  mass  exceeds  a  very  moderate  bulk  (in  breadth 
and  thickness)  the  processes  of  rolling,  &c.,  are  at  an  end;  those  of  forg- 
ing by  the  tilt  or  steam-hammer  alone  are  available.  Skilled  labor  and 
all  the  mishaps  to  which  the  results  of  the  most  adroit  workmanship  are 
exposed  in  dealing  with  the  heating  and  hammering  of  vast  and  scarce 
manageable  masses  are  inevitable.  The  mass  must  be  gradually  built 
up  and  aggrandized  in  size  by  continual  welding  on  to  it  of  small  pieces, 
involving  reiterated  heating  and  partial  cooling ;  exposure  for  weeks, 
perhaps,  to  a  temperature  at  which  the  exterior  of  the  mass  gets  changed 
more  or  less  in  chemical  constitution,  and  at  each  welding  the  risk  of 
inclusion  of  more  or  less  slag,  cinder,  or  other  foreign  matter. 

Late  experience  has  shown  me  that  in  very  large  cyliiidric  masses  of 
forged  wrought  iron,  (i.  e.,  of  three  feet  diameter  and  upwards,)  amongst 
the  other  abnormal  circumstances  involved  in  their  production,  is  that 
of  their  frequently*  rending  or  tearing,  internally,  in  planes  nearly 
parallel  with  and  about  the  axis,  though  not  always  in  it,  presenting 
characters  similar  to  those  described  in  section  217;  and  the  cause 
appears  to  be  that  in  the  progress  of  cooling  of  such  a  mass  the  exterior 
cools  first  and  becomes  rigid,  while  the  internal  portions  are  still  red-hot 
and  soft.  The  external  parts  would  contract  as  they  cool,  but  they 
already  grasp,  in  perfect  contact,  the  still  hot  interior;  the  exterior, 
therefore,  cannot  contract  fully,  but  becomes  solid  under  constraint  cir- 
cumferentially,  partly  itself  extended  in  virtue  of  its  compressing  the 
still  hot  and  soft  interior;  the  latter  at  length  also  becomes  cold  and 
rigid,  but  its  contraction  is  now  resisted  by  the  rigid  arch  of  the  exterior 
with  which  it  is  surrounded.  The  contraction  of  the  interior,  therefore, 
is  limited  to  taking  place  radially  outwards  from  the  center,  and  thus 
the  mass  rends  itself  asunder  in  some  one  or  more  planes  parallel  to  the 
axis  of  the  cylinder. 

In  a  cylindric  mass  of  forged  iron,  varying  from  24  to  36  inches  in 
diameter,  rents  of  18  inches  in  width  across  a  diameter  were  found  with 
jagged  counterpart  surfaces  clearly  torn  asunder,  and  about  three-fourths 
of  an  inch  apart  at  the  widest  or  central  part;  and  the  fact  is  most 
instructive  as  to  the  enormous  internal  strains  that  must  exist  from  like 
causes  in  cast-iron  guns  and  mortars  of  large  size. 


186  EXPERIMENTS    ON    HEAVY    ORDNANCE. 

It  is  probably  from  this  cause  that  more  or  less  hollo  wness  is  found  in 
the  centre  of  almost  every  large  forging,  greater  in  proportion  as  it  is 
larger.  The  difficulty  is  one  not  easily  overcome;  very  slow,  and,  as  far 
as  possible,  uniform  cooling  of  the  whole  mass  in  an  annealing  oven  sug- 
gests itself  as  one;  but  this  has  disadvantages  in  enlarging  the  crystal- 
line development  of  the  metal,  or  providing  a  central  cylindric  opening 
so  as  to  cool  both  the  circumference  and  the  center  together. 

EFFECT  OF  RE-MELTINGS  ON  THE  STRENGTH  AND  TEXTURE  OF  CAST- 
IRON. 

Extract  from  Nallett  on  Artillery. 

SECTION  25.  The  experiments  of  Mr.  Fairbairn  (Trans.  Brit.  Ass.,  1853) 
on  the  repeated  melting  of  the  same  cast-iron,  by  casting  into  inch 
square  bars,  are  concluded  by  him  to  prove  that  the  grain  of  the  metal 
and  the  physical  qualities  of  the  casting  improve  by  some  function  of 
the  number  of  meltings,  and  he  fixes  on  the  13th  melting  as  that  of 
greatest  strength. 

EFFECT  OF  HEAT  ON  GUNS. 

Extract  from  Mallett  on  Artillery. 

SECTION  89.  Applying  Professor  Hodgkinson's  experimental  results 
as  to  the  extensibility  of  cast-iron  under  strain  to  this  reasoning,  and 
taking  the  coefficient  of  expansion  by  heat  for  cast  and  wrought-iron  as 
the  same  for  low  temperatures,  (strictly  as  1000893,  1000894  for  tempera- 
tures under  212°,)  we  have  the  extension  for  cast  iron  for  the  square 
inch  of  section  equal  about  3^0 -Q  of  its  length  for  each  ton  of  load,  up  to 
seven  or  eight  tons,  at  which  its  elasticity  becomes  permanently  im- 
paired ;  that  is  to  say,  when  it  begins  to  lose  its  form.  An  equal  change 
of  length  is  due  to  eight  degrees  of  Fahrenheit  difference  in  tempera- 
ture. 

SECTION  90.  Let  us  now  assume  a  64  pound  shot  rammed  home  at 
2,000°  Fahrenheit,  which  is  under  a  Avhite  heat,  and  that  it  remains  50 
seconds  in  the  gun  while  the  latter  is  being  run  out  and  fired;  that  in 
this  interval  the  shot  transmits  T^  of  its  heat  to  an  equal  mass  of  the 
cold  gun,  and  that  the  whole  of  this  is  operative  in  expanding  a  cylin- 
dric ring  of  a  determinate  thickness  around  the  ball,  then  we  have 

F=^0=25  tons, 

as  the  mean  compressive  strain  per  square  inch  upon  this  interior  ring. 
But  as  the  ultimate  cohesion  of  cast  iron  does  not  exceed  about  eight 
tons  to  the  square  inch,  the  actual  effect  upon  the  strength  of  the  gun  is 
the  same,  as  if  about  three  inches  of  its  thickness  were  removed,  or  that 
an  inch  in  thickness  of  its  interior  metal  were  removed,  and  a  total  strain 
of  17  tons  were  at  the  same  time  visited  upon  the  remaining  section  of 
its  thickness.  At  such  a  conjuncture,  with  such  a  steady  strain  already 
on  its  metal,  the  gun  is  fired  and  an  additional  impulsive  strain,  equal 
to  the  work  done  in  giving  to  the  shot  its  initial  velocity,  is  suddenly 
brought  upon  its  material. 

This,  even  with  the  regulation  reduced  charge  for  hot  shot,  of  J  the 
service  charge  for  cold  shot,  is  seldom  less  than  2J  tons  on  the  square 
inch  of  section,  producing  from  the  impulsive  nature  of  the  force  an 
extension  equal  to  that  of  a  passive  strain  of  5  tons.  The  wonder,  then, 
is  rather  that  any  gun  stands  than  that  many  should  burst. 

SECTION  93.  A  train  of  effects,  quite  analogous  to  those  described, 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          187 

are  brought  into  operation  in  very  quick  firing,  whether  with  hot  or  cold 
shot,  when  the  interior  of  the  gun,  continually  receiving  fresh  accessions 
of  heat  from  the  rapidly  succeeding  flashes  of  powder,  is  not  given  time 
to  transmit  it  by  conduction  through  its  metal  to  the  exterior.  The 
limit  of  the  heat  that  could  be  conceived  communicated  from  one  dis- 
charge to  the  gun,  would  be  the  whole  of  that  generated  by  the  igni- 
tion of  the  charge.  Assuming  the  formula  for  gunpowder  to  be  K  O, 
NO5+S-I-C3,  its  atomic  weight  will  be  135,  and  one  part  by  weight  will 
include  0.1333  of  carbon.  Now,  Andrews  (Keports  Brit.  Assoc.,  1849,) 
found  that  one  part  of  carbon  evolves  as  much  heat  in  burning  as  will 
raise  an  equal  weight  of  water  7900°  Cent.  Hence,  neglecting  the  sul- 
phur as  not  oxidized  in  combustion,  the  heat  generated  by  the  firing  of 
any  charge  of  powder  is  sufficient  to  raise  the  temperature  of  an  equal 
weight  of  water  7900°  x  0.1333=1053°  Cent.=1895.4  Fahrenheit,  or  to 
boil  about  nine  times  its  own  weight  of  water,  or  to  heat  about  nine- 
teen times  (18.945  strictly)  its  weight  100°  Fahrenheit. 

SECTION  95.  In  this  case  (that  of  heating  by  quick  firing)  the  interior 
expansion  is  not  almost  limited,  as  in  the  former,  to  a  ring  in  the  imme- 
diate neighborhood  of  the  shot,  but  extends  to  the  whole  length  of  the 
chase  or  bore,  so  that  the  whqje  gun  becomes  lengthened  by  the  "  end 
on"  strain  of  its  expanded  interior. 

THE  MECHANICAL  EQUIVALENT  FOB  HEAT. 

Extracts  from  u  Sketch  of  Thermodynamics?  by  P.  Gr.  Tait,  M.A. 

It  is  very  remarkable  that  from  the  series  of  experiments  agreeing 
well  with  one  another,  which  were  made  with  this  simple  apparatus, 
Joule  deduced  as  the  dynamical  equivalent  of  heat  (that  is,  of  the  heat 
required  to  raise  the  temperature  of  a  pound  of  water  1°  F.)  770  foot- 
pounds, differing  by  only  about  a  quarter  per  cent,  from  the  results  of 
his  subsequent  and  far  more  elaborate  determinations.  The  close  agree- 
ment of  the  results  of  successive  trials  was  quite  sufficient  to  justify 
him  in  publishing  this,  as  in  all  probability  a  very  close  approximation 
to  the  desired  value  of  the  equivalent. 

(It  is  curious  that  the  mean  of  the  valves  deduced  from  Eumford's 
and  Colding's  experiments,  the  two  legitimate  ones  whose  publication 
preceded  that  of  this  result  of  Joule's,  differs  from  it  by  only  about  2J 
per  cent.) 

36.  Before  leaving  this  part  of  our  subject  it  may  be  desirable  to  com- 
plete the  enumeration  of  the  results  of  Joule's  direct  experiments  for  the 
determination  of  the  mechanical  equivalent,  as  they  are  certainly  supe- 
rior in  accuracy  to  those  of  any  other  experimenter. 

Kepeatiug  in  1845  and  1847  his  experiments  on  the  friction  of  water, 
but  now  by  means  of  a  horizontal  paddle,  turned  by  the  descent  of  known 
weights,  he  obtained  results  gradually  converging,  as  in  each  successive 
set  of  experiments  extraneous  causes  of  error  were  more  completely 
avoided  or  allowed  for.  The  value  of  the  equivalent  deduced  in  1847 
from  a  great  number  of  experiments  with  water  was  781.5  foot-pounds, 
and  with  sperm  oil,  782.1.  In  the  paper  of  1845,  we  find  his  first  specu 
lations  as  to  the  absolute  zero  of  temperature,  or  the  temperature  of  a 
body  absolutely  deprived  of  heat.  The  most  interesting  of  his  results 
are,  that  the  absolute  zero  of  temperature  is  480°  Fahr.  below  the  freez- 
ing point  of  water,  arid  that  a  pound  of  water  at  60°  Fahr.  possesses,  in 
virtue  of  its  heat,  mechanical  energy  to  the  enormous  amount  of  at  least 
415,000  foot-pounds.  Changes  have  since  been  shown  to  be  necessary  in 


188          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

these  numbers,  but  they  are  comparatively  unimportant.  And  it  must 
be  regarded  as  one  of  the  most  extraordinary  results  of  physical  science, 
that  a  pound  of  water  at  ordinary  temperatures  contains  heat  capable 
(if  it  could  be  applied)  of  raising  it  to  a  height  of  at  least  80  miles. 

37.  Finally,  in  1849,  Joule  published  the  results  of  his  latest  and  most 
elaborate  experiments,  of  which,  after  what  has  been  already  said,  the 
results  only  need  be  given : 

From  friction  of  water 772.692  foot-pounds. 

"          "        «   mercury 774.083        « 

"          «        «    cast-iron 774.987        " 

The  conclusion  of  this  valuable  paper,  after  all  allowance  is  made  for 
slight  but  inevitable  losses  of  energy,  by  sound  and  other  vibrations, 
are  thus  given : 

1st.  The  quantity  of  heat  producedby  the  friction  of  bodies,  whether  solid 
or  liquid,  is  always  proportional  to  the  quantity  of  icorTc  expended. 

2d.  The  quantity  of  heat  capable  of  increasing  the  temperature  of  a  pound 
of  water  (weighed  in  vacuo,  and  taken  at  between  55°  and  60° )  by  1°  Fahr., 
requires  for  its  evolution  the  expenditure  of  a  mechanical  force  represented 
by  the  fall  of  772  pounds  through  the  space  of  one  foot. 

It  is  only  necessary  to  observe,  that  the  determination  is  for  the  value 
of  gravity  at  Manchester,  and  must  of  course  be  diminished  for  higher, 
and  increased  for  lower  latitudes,  according  to  the  well-known  law. 

38.  As  no  one  has  yet  pretended  to  rival  in  accuracy  the  experiments 
of  Joule  above  mentioned,  and  as  his  celebrated  result  of  1843,  so  very 
close  to  the  truth,  preceded  all  other  recent  sound  attempts  to  determine 
the  mechanical  equivalent  of  heat,  the  results  of  direct  methods  since 
employed  by  other  observers  may  be  passed  over  with  the  remark,  that 

they  agree  more  or  less  perfectly  with  those  of  Joule. 

*  #  #  #  *  #  * 

87.  The  unit  for  measurement  of  work  usually  employed  by  British 
engineers  is  the  foot-pound;  and  though  this  varies  in  amount  from  one 
locality  to  another,  it  is  in  such  general  use  and  so  convenient  when 
absolute  accuracy  is  not  required  that  it  will  be  employed  throughout. 
It  is  the  amount  of  work  required  to  raise  a  pound  a  foot  high.  It  is 
evident  that  to  raise  any  mass  to  a  given  height  the  amount  of  work 
required  is  proportional  to  the  number  of  pounds  in  the  mass,  and  also 
to  the  number  of  feet  through  which  it  is  to  be  raised.  Thus,  to  raise  a 
hundred  weight  a  furlong  high  requires  the  same  expenditure  of  work 
(73.920  foot-pounds)  as  to  raise  a  stone-weight  a  mile  high,  or  a  pound 
14  miles.  And  the  potential  energy  of  the  raised  mass,  or  the  work 
which  can  be  got  out  of  it  in  virtue  of  its  position,  is  precisely  equivalent 
to  the  work  which  has  been  employed  in  raising  it. 

TIME  AND  TENSIONS — EFFECT  OF  TIME  ON  TENSIONS. 

Extracts  from  "  Experiments  on  Metals  for  Cannon  and  Cannon  Powder." 
Rodman,  p.  28.    Report  of  Captain  Rodman,  January  30,  1867. 

These  results  appear  to  leave  no  doubt  as  to  the  superiority  of  the 
hollow  over  the  solid  cast  guns,  while  new;  what  effect  time  may  have 
upon  them  can  only  be  ascertained  by  experiments  ;  but  it  is  difficult  to 
understand  how  time  could  ever  so  far  change  their  relative  endurance 

as  to  cause  the  solid  cast  guns  to  surpass  those  cast  hollow  in  this  quality. 

******* 

The  only  effect  of  time  is  supposed  to  be  to  relieve  the  metal  from 
the  strain  to  which  it  had  been  subjected  in  cooling,  it  not  being  sup- 
posed to  effect  any  change  in  its  actual  character. 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


189 


It  would,  therefore,  appear  to  be  reasonable  and  safe  to  predict  that  the 
utmost  effect  which  time  could  produce  would  be  to  bring  their  endurance 
to  an  equality ;  and  should  this  be  found  to  be  the  case,  which  is  not  prob- 
able, it  would  still  leave  the  hollow  cast  gun  superior  to  the  other  5  as  it  is 
believed  that  it  may  be  mounted  for  service  as  soon  as  finished,  and  relied 
on  for  at  least  150  rounds,  for  10-inch  guns ;  while  the  solid  cast  gun  cannot 
be  relied  on  for  a  single  fire  when  new ;  nor  can  any  limits,  below  which  it 
shall  be  safe,  be  with  any  degree  of  certainty  assigned  to  it  after  any 
lapse  of  time. 

The  cause  of  this  difference  is  believed  to  be  that  the  hollow  cast  gun 
is  so  far  relieved  from  strain  in  cooling  as  to  remove  the  possibility 
of  its  ever  being  injured  in  that  process  ;  and  the  more  perfect  this  relief, 
the  more  nearly  will  the  endurance  of  the  new  gun  approach  that  of  the 
same  gun  after  any  lapse  of  time. 

While  in  the  new  solid  cast  gun  it  is  certain  that  the  interior  is  under 
a  very  heavy  strain,  which  requires  time  for  its  removal ;  and  there  is 
no  certainty  that  this  strain  has  not  been  sufficiently  great  to  produce 
either  actual  cracks,  or  such  a  degree  of  molecular  separation  in  the 
interior  portions  of  the  gun  as  no  lapse  of  time  will  remedy. 

That  good  solid  cast  guns  may  be  made  is  not  doubted,  for  they  have 
been  made ;  but  that  it  is  possible  to  distinguish  before  the  trial  the 
safe  from  the  unsafe  gun  is  not  believed. 

Report  on  the  effect  of  time  in  removing  strains  caused  by  the  unequal  cooling 

of  heavy  iron  castings. 

PITTSBURGH  October  12, 1852. 

SIR  :  Since  my  report  of  the  24th  of  January  last,  on  the  manufacture 
and  extreme  proof  of  8-inch  and  10-inch  colunibiads,  Major  Bell  has  com- 
pleted the  extreme  proof  of  two  8-inch  coluuibiads,  cast  in  1846.  The 
extraordinary  endurance  of  these  two  guns  induces  me  to  submit  some 
further  considerations  upon  the  subject. 

The  mechanical  tests  and  the  endurance  in  firing  of  the  three  8-inch 
columbiads  are  as  follows : 


Density. 

Tenacity. 

No.  of  fires 
endured. 

Cast  and  proved  in  1851 

7  287 

37  811 

72 

Cast  in  1846  and  proved  in  1852          

7.247 

29,  423 

2,582 

Cast  and  proved  in  1852  ..  .             . 

7.  220 

22,  989 

800 

The  form,  dimensions,  weight,  method  of  casting  and  cooling,  and  the 
manner  of  proving,  were  the  same  in  all.  It  will  be  seen  that  the  gun 
made  of  the  strongest  iron,  with  a  short  interval  of  time  between  its 
manufacture  and  proof,  endured  the  smallest  number  of  fires  $  and  that 
those  made  of  weaker  iron,  but  proved  long  after  they  were  cast,  endured 
the  greatest  number  of  fires.  This  remarkable  feature  in  these  trials 
suggests  an  inquiry  as  to  the  cause  of  such  anomalous  results. 

In  the  former  report,  made  in  January  last,  the  character  and  the 
effects  of  the  strains  which  occur  in  the  cooling  of  iron,  when  cast  in  large 
masses,  are  stated  and  discussed.  But  now  it  appears,  from  the  results 
obtained  in  the  trials  since  made,  that  there  is  another  question  to  be 
considered ;  that  is,  longevity  of  such  strains,  or  the  length  of  time  during 
which  a  body  will  remain  under  a  strain,  without  a  renewal  of  the  strain- 
ing force. 


190          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

It  is  assumed  that  any  casting,  or  any  other  solid  body  will,  if  con- 
stantly strained  for  a  long  time,  adapt  itself,  in  part  at  least,  to  its  strained 
position,  and  lose  its  power  of  voluntary  restoration  to  its  original  posi- 
tion. 

Suppose,  for  example,  that  a  proof  bar  of  cast  iron  be  strained  in  the 
testing  machine  until  its  deflection  is  about  two-thirds  or  three-fourths 
of  that  which  it  will  endure  \vithout  breaking,  or  ulitil  the  deflection 
nearly  reaches  the  point  at  which  incipient  molecular  separation  occurs, 
and  that  the  pressure  be  then  removed ;  it  will  be  found  that  the  bar 
has  acquired  a  small  measure  only  of  permanent  set.  But  if  pressure  is 
not  removed,  or  if  removed  it  be  again  applied,  and  be  continued  a  long 
time,  it  will  be  found  that  the  bar  has  acquired  a  permanent  set,  nearly 
equal  to  its  deflection,  and  that  its  power  of  restoring  itself  to  its  original 
position  has  been  almost  entirely  lost.  Its  particles,  it  would  seem,  have 
adjusted  themselves  to  their  new  and  constrained  position,  and  become 
free,  or  nearly  so.  It  appears  that  they  resist  constraint  and  retain  the 
power  of  self-restoration  for  a  short  time  only  ;  but  if  the  restraint  be 
long  continued,  they  gradually  conform  themselves  to  it,  and  become 
passive  and  acquiescent. 

A  bar  which  has  thus  been  made  to  acquire  a  large  permanent  set,  it 
is  believed,  has  lost  but  a  small  portion  of  its  power  to  endure  renewed 
strains.  It  may  be  again  pressed  with  a  similar  force,  and  acquire  an 
additional  deflection  and  permanent  set,  nearly  or  quite  equal  to  that 
which  had  before  been  imparted  to  it.  By  repeating  this  process  at  long 
intervals  of  time,  the  permanent  set  of  a  bar  may  be  extended  much 
beyond  the  deflection  which  it  was  capable  of  enduring  when  it  was  first 
strained. 

Familiar  examples  of  the  facility  with  which  bodies  conform  to  con- 
strained positions  may  be  observed  in  the  hoops  of  common  barrels, 
whether  consisting  of  wood  or  of  iron.  The  hoops,  when  first  bent  around 
the  barrel,  lose  but  a  small  part  of  their  power  of  restoration,  but  when 
united  at  their  ends,  and  driven  firmly  down  upon  the  barrel,  they  soon 
lose  most  of  their  active  power  of  restoration,  become  passive,  and  acquire 
a  permanent  set,  conforming  nearly  to  the  circumference  011  which  they 
were  strained.  When  they  have  thus  acquired  this  permanent  set,  they 
may  be  further  bent  upon  smaller  circles,  until  reduced  to  a  curve  which, 
if  attempted  at  first,  would  have  broken  them,  while  the  strength  of  the 
hoop  will  remain  unimpaired.  If  solid  bodies  do  thus  relieve  themselves 
from  strains  produced  by  the  application  of  an  external  force,  why  may 
not  a  gun  casting  relieve  itself  in  like  manner  from  the  strains  caused  by 
unequal  cooling  ? 

The  strain  produced  in  cannon  by  unequal  cooling,  as  described  in  the 
preceding  reports,  is  one  of  compression  on  the  exterior  circumference, 
and  of  elongation  on  the  circumference  of  the  bore.  It  may  be  likened 
to  the  strain  which  would  exist  in  a  hollow  cylinder,  if  the  latter  be  cut 
through  its  thickness  in  one  of  its  elements,  and  the  fissure  be  afterwards 
enlarged  by  a  mechanical  force  acting  against  the  surfaces  of  the  fissure. 
A  strain  thus  produced  would  obviously  stretch  the  interior  surface  of 
the  cylinder,  and  compress  its  exterior  surface.  Now,  if  we  suppose  a 
strain  of  this  kind  to  be  so  far  extended  as  to  approach  nearly  to  the 
point  at  which  incipient  molecular  separation  occurs,  any  considerable 
addition  of  a  central  force,  of  any  kind,  will  evidently  produce  rupture. 
This  is,  I  believe,  the  condition  of  cannon  when  under  a  strain  caused  by 
unequal  cooling.  And  as  the  force  of  fired  gunpowder  acts  in  the  same 
direction,  a  few  fires,  if  made  soon  after  casting  the  cannon,  will  be  suffi- 
cient to  burst  it.  But  if  the  same  cannon  be  allowed  a  sufficient  time 


EXPERIMENTS  ON  HEAVY  ORDNANCE. 


191 


between  the  casting  and  proving',  to  free  itself  from  strain,  it  will  endure 
a  number  of  fires  proportioned  to  the  tenacity  of  the  metal  from  which 
it  is  made.  What  length  of  time  may  be  required  to  free  a  gun  from 
strain  can  be  ascertained  only  by  experiment  ;  but  it  will  doubtless  be 
found  to  be  proportioned  to  the  hardness  and  tenacity  of  the  iron,  and 
to  the  bulk  of  the  gun.  Hard,  strong  iron,  contracts  most,  and  conse- 
quently is  most  strained,  and  will  require  the  longest  time  to  relieve 
itself. 

On  this  hypothesis,  the  results  obtained  in  the  extreme  proofs  given 
in  the  preceding  tables  may  be  rationally  accounted  for.  If  we  refer  to 
the  8-inch  columbiads  cast  solid,  we  find  that  the  one  cast  in  1851,  and 
proved  in  30  days  after  it  was  cast,  or  say  in  about  three  weeks  after  it 
had  cooled,  we  find  that  with  a  tenacity  of  37,811,  it  only  endured  72 
fires ;  while  of  the  two  columbiads  of  the  same  model,  cast  in  1846  and 
proved  in  1852,  more  than  six  years  afterwards,  one  of  them,  with  a 
tenacity  of  22,989,  endured  800  fires,  and  the  other,  with  a  tenacity  of 
29,423,  endured  2,582  fires,  and  remains  unbroken. 

Results  so  remarkable  cannot  be  accounted  for  in  any  other  way,  that 
I  can  conceive,  than  on  the  assumed  hypothesis  before  mentioned,  viz : 
that  large  iron  castings,  when  cooled  from  the  exterior,  are  unavoidably 
strained  in  cooling,  and  that  such  strains,  if  within  the  limits  of  incipi- 
ent rupture,  are  removed  by  time,  leaving  the  casting  free. 

The  method  of  cooling  from  the  interior,  devised  by  Lieutenant  Eod- 
man,  tends  to  prevent  injurious  strains  in  cooling ;  and  if  the  method  be 
sufficiently  extended  on  this  principle,  a  strain  in  the  opposite  direction 
may  be  produced.  The  strain,  in  this  case,  would  be  one  of  compression 
on  the  surface  of  the  bore,  and  of  elongation  on  the  circumference  of  the 
gun ;  and  the  tendency  of  such  a  strain  would  be  to  prolong  the  endur- 
ance of  the  gun  beyond  the  proportion  of  fires  due  to  the  tenacity  of  its 
metal. 

This  theory  of  the  effect  produced  by  time  in  removing  strains  caused 
by  the  unequal  cooling  of  iron  castings,  appear  to  be  so  well  sustained 
by  the  facts  exhibited  in  the  experiments  cited,  and  its  bearing  upon  the 
subject  of  casting  heavy  cannon  appears  to  be  so  important,  that  I  have 
thought  it  my  duty  to  state  it,  and  to  submit  it  to  the  department. 
Eespectfully,  your  obedient  servant, 

W.  WADE. 

Colonel  H.  K.  CRAIG. 


THE  RODMAN  PRESSURE   INSTRUMENT. 

Extracts  from  "  Experiments  on  Metals  for  Cannon  and  Cannon  Powder." 

Rodman,  p.  197. 

Table  showing  the  velocity  of  shot,  in  feet  per  second,  and  pressure  of  gas  per  square  inch,  in 
pounds,  due  to  equal  columns  of  powder  behind  equal  columns  of  metal  when  fired  in  guns  of 
different  diameter  of  bore,  each  result  being  a  mean  of  lOJires. 


"o 

. 

o 

o 

Pressure  at  different  distances  from  bottom  of  bore. 

® 

I 

ll 

11 

1 

.5"° 

j9 

'*•§ 

*>  ** 

V 

At  bottom. 

At  14  in. 

At  28  in. 

At  42  in.' 

At  56  in. 

At  70  in. 

At  84  in. 

Q 

? 

F 

P 

|> 

In. 

ids. 

Lbs. 

7 

.07 

5.13 

74.44 

904 

36,  420 

15,  850 

8,370 

6,470 

6,850 

8,  050 

6,720 

9 

.09 

8.48 

124.  42 

883 

67,  100 

21,  100 

17,  759 

14,  900 

29,  475 

20,  970 

22,  825 

11 

.11 

12.67 

18G.  03 

927 

86,  750 

29,  300 

27,  800 

22,  420 

28,  400 

33,  850 

25,  050 

192          EXPERIMENTS  ON  HEAVY  OKDNANCE. 

The  points  most  worthy  of  note  in  these  results  are  the  very  marked 
increase  in  pressure  of  gas  as  the  diameter  of  bore  increases ;  and  that 
the  indications  of  pressure  are  greater  at  56  inches,  70  inches,  and  84 
inches  than  at  42  inches,  especially  in  the  9-inch  and  11-inch  guns. 

The  cause  of  the  difference  in  pressure  developed  in  these  guns  of  dif- 
ferent diameters  of  bores  is  believed  to  be  mainly  due  to  the  greater  heat 
developed  by  the  combustion  of  the  larger  mass  of  powder  in  the  large 
than  in  the  smaller  calibre,  and  perhaps,  also,  to  the  different  products 
of  combustion  formed  under  this  increased  temperature  and  pressure, 
and  partly  to  the  greater  cooling  surface  in  proportion  to  the  weight  of 
charge  in  the  small  than  in  the  larger  calibre. 

UNCERTAINTIES  AND    INCONGRUITIES    CONNECTED    WITH    THE    FABRI- 
CATION OF  GUNS. 

Extracts  from  report  of  Captain  J.  T.  Rodman — experiments  on  metals  for 
cannon  and  cannon  powder. 

This  investigation  is  ordered  as  a  probable  explanation  of  the  differ- 
ence in  endurance  of  guns  cast  and  cooled  in  the  same  manner,  made 
from  iron  of  the  same  qualities,  treated  in  nearly  the  same  manner,  and 
differing  but  slightly  in  quality  in  the  guns  themselves.  Probability, 
however,  is  not  Jcnowledge^  but  it  is  the  most  that  can  now  be  offered  as 
well  upon  this  as  upon  many  other  points  of  equal  importance. 

We  do  not  know,  for  example,  what  qualities  of  iron  are  necessary  to 
make  the  best  gun ;  nor,  if  we  did,  do  we  know  how,  from  any  of  its  ores, 
constantly  to  produce  iron  which  shall  possess  those  qualities. 

We  do  not  know  whether  guns  should  be  cast  hollow  or  solid,  nor  the 
proper  rate  of  cooling  for  either  mode  of  casting. 

We  do  not  know  the  best  exterior  model  for  guns,  nor  whether  those 
of  large  calibre  should  be  made  with  or  without  chambers. 

We  do  not  knoie  the  effects  of  time  upon  the  endurance  of  guns — 
whether  they  are  better  when  new,  or  after  they  have  lain  unused  for 
any  given  length  of  time. 

We  do  not  know  the  maximum  statical  pressure  due  to  a  given  weight 
of  powder  and  shot,  nor  how  much  the  rate  of  combustion  of  the  charge, 
or  the  rate  of  application  of  the  force,  causes  the  bursting  tendency  to 
exceed  that  due  to  the  statical  pressure. 

We  do  not  know  the  difference  in  endurance  due  to  a  given  difference 
in  bursting  tendency  at  each  discharge,  nor  what  weight  of  projectile  is 
equivalent  in  bursting  tendency  to  a  given  weight  of  powder,  nor  the 
difference  in  endurance  due  to  a  given  difference  in  thickness  of  metal. 

We  do  not  know  the  difference  in  bursting  tendency  due  to  a  given 
difference  in  temperature  of  the  same  charge  of  powder  at  the  moment  of 
ignition. 

Nor  do  we  know  the  proper  constitution  of  charge  in  order  to  produce 
a  given  velocity  of  projectile  with  the  minimum  bursting  tendency  of 
the  gun.  *  *  *  *  * 

There  is  no  other  known  cause  for  any  considerable  difference,  yet  we 
cannot  with  certainty  announce  this  as  the  only  cause,  for  a  single  result 
is  not  conclusive ;  and  differences,  almost  if  not  quite  as  great,  in  the 
endurance  of  solid-cast  guns,  have  been  found  to  exist,  without  any  known 
cause. 

#  *  *  *  #  * 

The  cascabel  dropped  off  the  solid-cast  gun  at  the  761st  fire,  and  a 
number  of  cracks  were  discovered  in  the  face  of  the  muzzle  after  the 


EXPEKIMENTS  ON  HEAVY  ORDNANCE.          193 

1209th  fire,  some  extending  back  three  or  four  inches.  These  cracks 
have  not  since  increased,  and  are  believed  to  be  due  to  some  accidental 
cause,  rather  than  to  the  regular  deterioration  of  the  gun  from  firing. 

The  cascabel  dropped  oif  the  hollow-cast  gun  at  the  1,379th  fire.  All 
the  trunnions  of  both  guns  are  slightly  cracked  at  the  junctions  of  the 
guns  and  rimbases,  the  left  trunnion  of  the  hollow  gun  apparently  the 
worst. 

There  is  a  very  marked  difference  in  the  interior  appearance  of  the 
two  guns,  the  bore  of  the  solid-cast  gun  being  greatly  more  deteriorated 
than  that  of  the  hollow-cast  gun. 

There  are  three  cracks  radiating  from  the  interior  of  the  first,  and  one 
from  that  of  the  second  vent,  in  the  solid  gun.  Those  from  the  first  vent 
are  from  two  to  three  inches  long,  running  in  an  almost  transverse 
direction  around  towards  the  first  vent. 

There  are  no  cracks  perceptible  in  the  hollow  gun. 

Extract  from  the  report  ofi  tlie  Joint  Committee  on  the  Conduct  of  the  War. 

It  is,  therefore,  of  the  highest  importance  to  obtain,  if  possible,  some 
kind  of  heavy  ordnance  which  shall  not  be  liable  to  these  objections. 
The  entire  efficiency  of  an  iron-clad  vessel,  costing  the  government  hun- 
dreds of  thousands  of  dollars,  may  depend  almost  entirely  upon  the 
character  of  the  guns  with  which  she  is  armed.  In  the  words  of  the 
Assistant  Secretary  of  the  Navy,  "you  might  lose  a  battle  by  going  into 
action  with  a  gun  around  which  stood  25  men  entertaining  the  idea  all 
the,  time  that  it  might  burst."  Considering  the  great  cost  of  our  iron- 
clad vessels,  and  the  importance  of  the  results  to  be  attained,  by  render- 
ing them  as  secure  and  efficacious  as  possible,  a  few  thousand  dollars  more 
of  expense  would  seem  to  be  of  but  little  moment,  if  it  affords  the  only 
means  of  reaching  the  end  desired.  The  disastrous  results  attending  the 
bursting  of  a  gun  can  be,  to  a  greater  extent,  guarded  against  upon  land 
than  at  sea.  In  the  latter  case  the  loss  of  the  vessel,  with  all  on  board, 
may  be  the  consequence,  while  the  demoralization  of  the  crews  of  the 
other  vessels  similarly  armed  may  lead  to  results  almost,  if  not  quite,  as 
disastrous.  But,  upon  both  land  and  sea,  it  is  of  the  utmost  importance 
to  obtain  heavy  ordnance  of  the  most  reliable  character. 

»'''"#  *  *  *  * 

The  bursting  of  these  guns  is  generally  attributed  to  the  explosion  of 
shells,  prematurely,  within  the  bore  of  the  gun.  The  opinion  of  Mr. 
Parrott,  in  regard  to  the  cause  or  causes  of  premature  explosion  of  the 
shells,  is  as  follows : 

It  has  been  a  matter  of  much  concern  with  me,  and  I  would  rather  not  make  a  gun  than 
have  any  accident  occur.  I  ascribe  the  difficulty  to  the  friction  of  the  powder  in  the 
shell  itself.  At  first  it  was  natural  enough  to  ascribe  the  difficulty  to  bad  shells,  bad 
castings,  bad  fuzes,  &c. ;  but,  upon  full  trial,  it  appears  above  all  question  that  the  diffi- 
culty arises  from  the  powder  exploding  in  the  shell  within  the  gun  by  friction,  caused  by 
the  striking  of  the  powder  against  the  inside  of  the  shell.  A  300-pounder  shell  is  10  inches 
in  diameter;  a  round  shell  of  that  diameter  holds  about  three  pounds  of  powder.  My  300- 
pounder  shell  holds  about  17  pounds  of  powder.  Now,  when  you  fire  a  gun,  and  strike  the 
butt  of  a  shell  suddenly  with  the  immense  force  of  the  charge,  there  is  a  reaction  of  the  pow- 
der within  the  shell  against  the  bottom  of  the  shell,  and  if  there  is  any  roughness  so  as  to 
cause  friction  at  the  bottom,  the  powder  will  be  exploded  in  the  shell  while  it  is  within  the- 
gun.,  Thinking  that  to  be  the  case,  I  have  for  a  long  time  been  endeavoring  to  coat  the 
inside  of  the  shell  with  varnish  or  lacker,  and  I  am  able  to  do  it  with  entire  success.  A 
great  many  people  were  skeptical  about  it,  and  precautions  have  not  been  taken,  in  regard 
to  it,  as  quickly  as  they  might  have  been.  I  now  melt  together  rosin,  tallow  and  brown 
soap,  forming  a  thin  liquid  mixture,  and  pour  it  into  my  shells  and  pour  it  out  again,  leaving 
a  coating  on  the  inside  which  covers  over  the  rough  iron,  and  when  that  is  done  I  find  the 
shells  can  be  fired  without  premature  explosion. 

Rep.  No.  266 13 


194          EXPEKIMENTS  ON  HEAVY  ORDNANCE. 

Some  two  months  ago  Captain  Temple,  one  of  the  officers  of  this  very  fleet  of  Porter's, 
came  to  the  foundry  and  became  aware  of  this  fact.  He  had  two  100-pounders  on  board  his 
vessel ;  when  he  got  back  he  found  that  his  shells  had  no  such  coating,  and  he  immediately 
set  to  work  and  lined  them  with  asphaltum,  &c.  He  fired  his  guns  50  or  60  times  each 
during  the  engagement,  and  not  a  single  shell  exploded  prematurely  in  his  guns  ;  while  in 
some  of  the  other  vessels  around  him  shells  were  exploded  prematurely,  and  thrown  out  of 
the  guns  in  fragments. 

That  is  so  stated  in  a  letter  of  his  which  I  saw  yesterday. 

Be  the  cause  or  causes  what  they  may  be,  the  fact  is  that  these  guns 
do  burst  while  in  action,  with  very  disastrous  results. 

Extract  from  tlie  testimony  of  Brigadier  General  George  D.  Ramsay  before 
the  Joint  Committee  on  the  Conduct  of  the  War,  p.  12. 

Q.  I  cannot  myself  see  why  it  would  not  be  easy  to  take  a  100-pounder 
Parrott  gun,  for  instance,  and  a  100- pounder  Kodm  an,  and  subject  them 
to  certain  tests  of  powder  and  ball,  and  ascertain  which  is  really  the 
most  energetic  gun,  and  which  will  stand  the  most  charges. 

A.  There  would  be  no  difficulty  about  it,  aH  things  equal.  Some  of 
the  Parrott  guns  have  burst  before  Charleston.  This,  however,  is  ascri  bed 
'to  various  causes,  one  of  which  is  the  frequent  explosion  of  the  shell  in 
the  gun,  and  the  introduction  of  sand  into  the  bore. 

Q.  That  would  be  no  evidence  of  the  power  and  strength  of  the  gun 
when  properly  fired. 

A.  No,  sir. 

RATIO  OF  GOOD  AND  BAD  GUNS. 

Extracts  from  the  report  of  Captain  J.   T.  Rodman. — Experiments  on 
metals  for  cannon  and  cannon  powder. 

Out  of  seven  solid-cast  experimental  columbiads,  one  gun  only  proved 
to  be  good. 

Out  of  six  hollow-cast  columbiads,  three  were  good,  having  been  fired 
1,500,  1,600,  and  2,452  rounds  respectively,  and  neither  gun  broken. 

It  is  not  deemed  out  of  place  here,  in  order  to  show  the  necessity  of 
further  investigations  into  the  properties  of  cast  iron  in  its  application 
to  the  manufacture  of  cannon,  to  notice  some  facts  in  the  history  of  gun- 
founding  in  the  country  since  1849. 

The  very  low  endurance  of  the  first  pair  (8-inch)  of  experimental  guns 
which  were  cast  in  that  year  was  attributed  to  the  inferior  quality  of 
the  iron  of  which  they  were  made.  Two  years  were  spent  in  searching 
after  a  better  quality  of  iron,  which  was  undoubtedly  found,  and  in  1851 
another  pair  of  8-inch  guns  was  cast.  The  iron  in  this  pair  of  guns  has 
a  tenacity  of  near  38,000  pounds,  while  that  of  the  iron  in  the  first  pair 
was  only  between  27,000  and  28,000  pounds. 

The  solid-cast  gun  of  the  first  pair  burst  at  the  85th  fire,  and  that  of 
the  second  pair  at  the  73d  fire,  the  superior  iron  giving  the  inferior  solid- 
cast  gun. 

These  results  did  not,  however,  destroy  confidence  in  strong  iron  for 
solid-cast  guns,  and  the  first  pair  of  10-inch  guns  was  made  from  the  same 
lot  of  iron,  and,  with  a  tenacity  of  iron  of  37,000  pounds,  the  solid-cast 
gun  burst  at  the  20th  fire.  This  result  weakened  confidence  in  very 
strong  iron,  and  the  tenacity  was  reduced. 

In  1857,  after  guns  of  good  tenacity  had  failed  at  the  Fort  Pitt,  South 
Boston,  and  West  Point  foundries,  four  out  of  seven  guns  offered  for 
inspection  at  the  last-named  foundry  having  burst  in  the  proof,  Mr. 
Parrott,  proprietor  of  the  West  Point  foundry,  one  of  our  most  experienced 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  195 

gun-founders,  cast  his  trial  contract  guns  of  iron,  having  a  tenacity  of 
30,000  .to  32,000  pounds.  One  of  these  guns  has  endured  1,000  service 
charges  of  14  pounds  powder,  (800  rounds  with  shells  and  200  with  shot.) 

The  iron  selected  at  that  foundry,  and  from  which  the  last  five  experi- 
mental guns  have  been  made,  was  of  the  same  quality,  and  in  the  same 
proportions,  as  in  the  guns  last  above  referred  to. 

In  1858,  after  the  failure,  at  the  169th  fire,  of  the  West  Point  experi- 
mental gun  made  from  this  iron,  Mr.  Parrott  condemned  it  as  being  too 
high  for  heavy  guns. 

From  this  rejected  iron  was  made  the  last  pair,  Nos.  362  and  363,  of 
trial  10-inch  guns,  at  the  Fort  Pitt  foundry,  which  have  been  fired  2,452 
rounds  each,  the  least  charges  fired  being  14  pounds  powder  and  one 
solid  shot,  and  neither  gun  broke.  These  guns  have  since  been  fired 
1,000  rounds  each,  with  18  pounds  of  powder,  and  solid  shot,  and  neither 
gun  got  broken. 

It  should  also  be  borne  in  mind  that  the  proprietors  of  the  West  Point 
foundry  have  control  of  the  smelting  furnace  at  which  their  gun-iron  is 
made;  they  ought,  consequently,  to  have  a  more  perfect  knowledge  of 
the  qualities  and  properties  of  their  iron  than  those  founders  who  are 
dependent  upon  the  market  for  their  iron. 

These  facts  to  my  mind  are  conclusive  as  to  the  fact  that  we  are  at 
present  far  from  possessing  a  practical  knowledge  of  the  properties  of 
cast  iron  in  its  application  to  gun-founding;  and  it  is  too  much  to 
expect  of  private  enterprise  to  take  up  and  prosecute  so  intricate  and 
expensive  an  inquiry. 

Extract  from  the  testimony  of  Brigadier  General  George  D.  Ramsay  before 
the  Joint  Committee  on  the  Conduct  of  the  War. 

Q.  You  have  stated  the  tests  to  which  these  guns  were  subjected. 
What  reason  is  there  for  believing  that  these  tests  are  satisfactory; 
what  reason  have  you  for  placing  confidence  in  them  ? 

A.  The  reliability  of  the  experiments,  as  shown  by  the  endurance 
of  the  guns. 

Q.  You  think  they  are  satisfactory? 

A.  Yes,  sir;  every  effort  has  been  made  to  render  them  so. 
****** 

Q.  You  consider  the  Eodman  gun  the  best  gun  now  in  use? 

A.  Yes,  so  far  as  guns  made  entirely  of  cast  iron  are  concerned. 

Q.  What  tests  have  been  applied  to  the  Rodman  gun  I 

A.  First,  there  is  the  preliminary  test  of  ores,  which  embrace  all  the 
scientific  investigations  deemed  necessary.  Castings  from  the  ores 
selected  are  tested  for  density  and  tenacity.  Experiments  have  estab- 
lished standards  below  which  guns  are  not  received.  Then  comes  the 
powder  proof.  The  only  proof  to  which  guns  were  formerly  subjected 
was  by  using  excessive  charges ;  but  this  was  found  to  be  objectionable, 
and  not  reliable,  as  there  was  no  assurance  that  after  all  the  trials  with 
heavy  charges  the  gun  would  not,  as  often  happened,  burst  with  the 
ordinary  service  charge.  Confidence  was  greatly  impaired,  and  many 
serious  accidents  from  bursting  ensued.  I  refer  to  guns  cast  solid.  The 
theory  of  Captain  Eodman  being  undoubtedly  correct,  experiments  were 
made  in  order  to  verify  or  refute  it  in  a  practical  manner.  Several  sets 
of  cannon  of  the  same  form  and  calibre  were  cast,  part  in  the  ordinary 
method  of  casting  solid  and  cooling  from  the  exterior,  and  the  same 
number  on  Rodman's  plan.  These  were  fired  alternately,  alongside  of 
each  other,  with  charges  of  powder  and  ball  of  the  same  weight  and 
kind,  and  continued  until  one  or  the  other  class  of  cannon  gave  way 


196  EXPEKIMENTS  ON  HEAVY  ORDNANCE. 

under  the  repeated  firing.  The  result  of  these  trials  on  several  sets  of 
cannon  showed  conclusively  a  far  greater  endurance  for  the  Rodman 
gun,  more  than  300  per  cent,  greater  than  those  cast  in  the  ordinary 
way  ;  that  is  to  say,  we  could  rely  on  getting  as  much  firing  from  one 
Rodman  gun  as  from  three  guns  cast  solid  in  the  usual  way.  Besides 
this  greater  durability,  the  Rodman  gun  possesses  the  greater  advan- 
tage of  reliability  in  use  ;  that  is  to  say,  being  served  without  danger  to 
the  men  standing  by  it  from  bursting  of  the  piece. 

Q.  The  powder  test  is  the  test  by  powder  and  ball — the  service  charge  ? 

A.  Yes,  sir ;  and  when  a  new  kind  of  gun  or  ore  is  introduced,  the 
trial  is  1,000  pounds. 

MODELS  OF  aims. 

Extract  from  the  testimony  of  Brigadier  General  George  D.  Ramsay  before 
the  Joint  Committee  on  the  Conduct  of  the  War,  p.  10. 

Q.  I  understand  you  that  this  Rodman  gun  was  shaped  after  the 
experiments  of  Colonel  Boinford,  to  ascertain  where  the  greatest  strain 
would  come? 

A.  Yes,  sir ;  but  whether  Captain  Rodman  had  these  in  view  when 
he  investigated  the  subject,  (which  investigation  will  be  found  in  a  work 
of  high  reputation  on  experiments  on  metals  for  cannon  and  cannon 
powder,  by  Captain  Rodman,)  I  am  not  prepared  to  say.  As  to  the 
shape  of  the  gun,  Commander  Dahlgren,  in  a  letter  to  Secretary  Floyd, 
accused  Captain  Rodman  of  plagiarism,  on  the  completion  of  his  (Rod- 
man's) 15-inch,  and  which  led  to  a  correspondence  between  these  officers. 
Rodman's  gun  conforms  more  in  exterior  shape  to  the  columbiad  than 
the  Dahlgren. 

Q.  Does  the  advantage  of  the  Rodman  plan  consist  in  the  fact  that 
the  gun  cast  hollow  with  a  stream  of  cold  water  poured  through  the 
inside  ? 

A.  Yes,  as  regards  the  casting.  But  the  Rodman  gun  embraces  more 
than  this — the  exterior  form.  Formerly  guns  were  in  their  exterior 
form  a  series  of  sections  of  straight  lines,  called  reinforce,  somewhat 
analogous  to  the  joints  of  a  telescope  when  drawn  out,  but  the  Rodman 
gun  (which  the  witness  illustrated  by  a  diagram  on  a  piece  of  paper) 
gives  a  curved  section.  The  thickness  at  the  seat  of  the  charge  in  cast- 
iron  guns  is  a  little  more  than  the  diameter  of  bore,  gradually  tapering 
to  the  muzzle.  Some  twenty  years  ago  the  late  Colonel  Boinford  insti- 
tuted a  series  of  interesting  and  original  experiments  to  determine  the 
expansive  force  with  which  fired  gunpowder  acts  at  different  points  along 
the  bore  of  the  gun  and  with  the  view  of  ascertaining  the  requisite  curve 
of  resistance;  that  is  to  say,  at  what  points  the  metal  received  the 
greatest  strain,  and  consequently  where  the  greatest  thickness  was 
necessary.  From  these  experiments  the  columbiad — a  gun  so  called — 
originated,  and  to  which  may  be  traced  the  French  Paixhan  gun.  The 
columbiads  were  originally  made  with  chambers,  and  are  now  used  for 
shot  and  shell.  Colonel  Bomford  did  not  pursue  his  investigation  beyond 
determining  the  above  facts.  These  experiments  satisfactorily  show  that 
the  greatest  force  of  the  charge  is  exerted  on  the  part  of  the  gun  which 
is  situated  in  rear  of  the  centre  of  the  ball,  and  the  force  diminishes 
rapidly  as  the  ball  moves  forward  from  its  orignial  position. 

Q.  When  was  this  investigation  I 

A.  About  1843.  It  is  understood  that  a  French  ofiicer,  General  Paix- 
han, when  on  a  visit  to  this  country,  was  made  acquainted  with  the  exper- 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  197 

iments  of  Colonel  Bomford,  and  on  returning  home  he  introduced  a 
similar  gun  into  the  French  service,  the  Paixhan  gun,  as  a  shell  gun. 

Q.  Then  I  understand  you  the  principle  is  an  old  one  ? 

A.  Not  the  principle  of  cooling  from  the  interior. 

Q.  The  shape  of  the  gun? 

A.  This  shape  of  gun  is  yet  somewhat  a  matter  of  contention.  It 
matters  not  what  the  shape  of  the  gun  is,  within  certain  limits,  if  cast 
on  correct  principles. 

Q.  Describe  the  Dahlgren  gun  and  the  Bodman  gun,  and  its  advantage 
over  the  Rodman  gun  or  coluinbiad. 

A.  The  Dahlgren  gun  is  cast  solid  and  cooled  from  the  exterior.  The 
diameter  of  the  rough  casting  at  the  chase  is  much  greater  than  that  of 
the  finished  gun ;  the  surplus  metal  is  turned  off  into  the  lathe.  The 
Eodman  gun  and  the  columbiads  are  cast  hollow  and  cooled  from  the 
interior.  The. advantages  of  one  form  of  gun  over  another  is  an  open 
question,  and  it  matters  not,  within  certain  limits,  if  the  gun  is  cast  on 
correct  principles,  such  as  Rodman's,  as  before  stated.  But  as  to  the 
advantages  of  casting  very  heavy  guns  on  Rodman's  plan,  the  Navy 
Bureau  of  Ordnance  has  shown  its  confidence  in  the  method  of  having 
them  so  cast  at  the  present  time. 

Q.  Has  either  one  of  those  guns  any  advantage  over  the  other  in  actual 
use  or  practice  ? 

A.  In  practice  the  Rodman  gun  cast  hollow,  in  my  opinion,  must  have 
decided  advantages  as  to  endurance;  as  to  range,  this  will  depend  upon 
the  circumstances  under  which  they  are  fired. 

EXPERIMENTS  AT  SHOEBTJRYNESS. 

From  the  London  Times. 
v 

The  late  trials  of  the  15-inch  American  gun  and  the  English  rifled 
mountain  gun  for  the  Abyssinian  expedition  have  been  full  of  interest. 
The  heaviest  smooth-bore  and  the  lightest  rifled  gun  in  England  were 
fired  side  by  side.  The  experiments  with  the  American  gun  have  not 
led  to  any  desire  on  the  part  of  English  artillerists  to  adopt  the  system, 
but  we  hasten  to  admit  that  the  huge  Rodman  is  a  magnificent  gun  of 
its  kind,  and  shows  a  process  in  the  manufacture  of  cast  iron  which 
does  the  gallant  officer  who  has  devoted  himself  to  that  branch  of  artil- 
lery science  infinite  credit.  It  is  curious  that  both  American  and  Eng- 
lish pieces  of  heavy  ordnance  are  showing  signs  of  far  greater  endurance 
than  was  foretold  by  their  respective  backers.  When  first  the  Rodman 
guns  were  issued  for  service,  60  pounds  of  their  service  powder,  what- 
ever it  may  be  called,  was  considered  the  highest  charge  that  could  be 
fired  from  it  with  safety,  and  that  only  a  few  rounds.  The  English  9-inch 
gun  in  the  same  manner  was  allowed  only  150  rounds,  with  its  battering 
charge,  and  400  rounds  were  named  as  constituting  its  probable  life  if 
the  whole  150  battering  charges  were  to  be  used  in  it.  Since  then  the 
Rodman  has  been  fired  at  Fortress  Monroe  with  100  pounds  of  powder, 
and  a  like  trial  at  Shoeburyness  has  shown  that  the  feat  can  be  repeated, 
but  we  have  yet  to  learn  how  often  with  the  same  gun.  One  of  our 
9-inch  rifled  guns  has  stood  1,043  rounds,  680  of  which  were  with  battery 
charges,  some  as  high  as  50  pounds,  and  the  gun,  though  much  eaten 
away  in  the  interior,  is  still  capable  of  offence.  Two  other  9-iuch  guns 
have  been  fired  500  rounds  each  with  battering  charges,  and  are  still  in 
excellent  condition.  We  do  not  consider  our  13-inch  rifled  gun  a  success, 
but  it  was  fired  several  times  with  100  pounds  of  strong  English  powder 
without  bursting,  and  when  two  shot  struck  near  each  other  the  second 


198          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

passed  through  the  Hercules  target,  which  is  probably  the  stroDgest  yet 
constructed. 

It  is  very  necessary  in  the  comparison  of  different  artillery  systems 
to  distinguish  between  the  many  different  questions  involved.  In  the 
present  almost  international  competition  the  principal  questions  are: 
1st.  Backing  v.  punching;  2d.  Comparative  penetration;  3d.  Killed  v. 
smooth-bore  guns;  4th.  The  material  of  which  the, national  ordnance  is 
to  be  made.  The  difference  between  gunpowder  is  hardly  a  question, 
because,  though  ours  is  stronger  than  the  American,  we  do  not  claim 
any  advantage  in  that  respect,  but  rather  the  contrary,  because  quick- 
burning  powder  is  too  severe  on  the  gun.  The  name  by  which  the  Ameri- 
can powder  used  in  the  late  experiments  is  known  to  the  United  States 
authorities  is  hardly  settled  yet,  for  there  are  many  gunpowders  in  their 
list,  and  though  the  present  sample  is  not  the  largest  mammoth  powder 
such  as  was  meant  when  we  were  told  that  50  pounds  of  it  only  equalled 
in  strength  35  pounds  of  No.  7  cannon  powder,  neither  does  it  appear 
to  correspond  with  the  size  of  grain  laid  down  for  this  latter.  It  is 
perhaps  something  between  the  two,  and  its  name  is  still  uncertain. 
"American  service  powder"  was  the  name  used  in  contracting  for  it, 
and  "American  service  powder"  it  is,  of  a  strength  one-sixth  less  than 
English  powder  for  heavy  guns,  whatever  may  be  its  exact  title. 

No  one  at  all  acquainted  with  the  subject  can  deny,  in  the  face  of  all 
experiments  made  throughout  the  world,  that  elongated  shot  are  better 
calculated  for  penetration  than  round  ones,  nor  did  the  Americans  deny 
this  when  they  first  produced  their  heavy  guns.  They  said  that  they 
did  not  wish  to  perforate  or  "punch"  targets,  but  to  smash  them  to 
pieces  or  "rack"  them.  Their  ships  were  protected  with  "laminated" 
armor,  by  which  is  meant  armor  composed  of  several  one-inch  plates  laid 
upon  each  other  and  plated  together.  This  is  a  kind  of  structure  easily 
shattered,  and  even  far  more  vulnerable  to  punching  guns  than  solid 
plates,  or  a  lesser  number  of  thicker  plates.  English  constructors  saw 
no  difficulty  in  building  ships  that  could  not  be  -racked  by  guns  of  the 
power  set  forth  in  American  publications,  and  the  result  of  the  late 
experiments  has  proved  the  truth  of  the  assertion.  It  was  only  at  close 
quarters  and  with  charges  of  60  pounds — too  much  for  continued  firing, 
according  to  their  own  authorities — that  officers  were  allowed  to  attempt 
to  penetrate  a  strong  iron-clad  ship'.  The  contest  between  the  advocates 
of  racking  and  punching  was  hot,  and  we  were  unprepared  for  the  vexa- 
tion exhibited  throughout  the  Unites  States  when  it  was  found  that 
their  cast-iron  and  even  our  steel  shot  fired  from  their  gun  failed  to 
penetrate  the  target.  If  penetration  and  not  racking  merely  be  now 
claimed  for  their  guns,  the  only  points  to  be  assured  of  are  these.  Is 
the  average  strength  of  a  15-inch  gun  sufficient  to  enable  their  naval 
and  military  authorities  to  authorize  the  employment  of  100-pound 
charges,  and,  if  so,  will  the  projectiles  which  they  use  hold  together 
long  enough  to  get  through  when  they  strike?  A  steel  shot  with  1,500 
feet  of  velocity  will  penetrate  the  8-inch  plate  and  Warrior  backing.  A 
cast-iron  shot  mayor  may  not,  according  to  the  excellence  of  its  material. 
Probably,  but  not  certainly,  it  will  penetrate.  Certainly  neither  of  them 
will  perforate  the  Hercules. 

It  is  very  instructive  to  look  back  a  little  and  see  how  short  a  time 
has  elapsed  since  the  object  of  iron-clads  was  supposed  to  be  the  keep- 
ing out  of,  shells.  Mr.  WhitworthTs  achievement  when  he  fired  a  steel 
shell  through  the  Warrior  target  rang  through  Europe,  and  now  chilled 
shells  with  oval  heads  have  a  power  of  penetration  superior  to  that  of 
shot.  The  9-inch  gun  sends  its  shells  through  the  8-iuch  target,  and  we 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          199 

know  that  no  round  shells  from  the  15-inch  Rodman  have  a  chance  of 
piercing  it,  whatever  may  be  the  success  of  their  shot.  And  then,  be 
it  remembered,  this  15-inch  gun  weighs  seven  tons  and  a  quarter  more 
than  the  English  9  inch. 

Many  honest  inquirers  who  are  watching  the  results  of  the  trials  may 
say,  "  There  is  something  very  odd  about  this  matter.  What  is  the  virtue 
of  the  English  gun  that  it  can  send  its  lighter  projectiles  with  lighter 
charges  through  a  target  that  resists  a  far  greater  expenditure  of  ammu- 
nition on  the  part  of  the  American  gun?  Is  it  quite  fair  not  to  use 
chilled  shot  or  shells  which  are  so  cheap  and  strong  in  both  cases?"  It 
is  fair,  and,  indeed,  it  would  be  very  unfair  to  the  American  gun  to  put 
chilled  projectiles  into  it,  and  estimate  its  force  by  their  effect.  One 
chilled,  or  rather  white  iron  shot,  was  fired  from  it  at  the  8-inch  target, 
and  did  least  damage  of  the  three  hurled  against  it  on  the  same  day,  as 
would  have  been  predicted  beforehand  by  all  who  understand  this  not 
very  abstruse  question.  White  iron  projectiles  are  very  brittle,  and  are 
of  little  use  unless  they  have  sharp  points  and  are  driven  point  foremost, 
which  can  only  be  done  if  the  gun  is  rifled. 

The  range  at  32  degrees  elevation  and  with  100  pounds  charge  was 
7,680  yards,  the  initial  velocity  about  1,538  feet  a  second;  1,600  feet  a 
second  is  a  common  velocity  for  smooth-bores,  and  much  higher  speed 
has  jDeen  attained  in  the  wrought-iron  guns  constructed  some  years  ago 
for  the  navy.  The  Rodman  gun  is  probably  too  short  to  burn  all  the 
powder  before  the  shot  leaves  the  muzzle,  and  a  further  increase  of 
charge  would  not  give  proportionate  velocity.  Sixty  pounds  gives  1,170 
feet  per  second;  100  pounds  only  increases  it  to  1,538  feet;  quite  enough, 
however,  to  force  an  entrance  into  any  of  our  ships  at  present  afloat,  if 
the  range  is  short,  and  if  the  gun  is  fired  at  right  angles  to  the  side  of 
the  ship.  The  least  angle  will  affect  your  round  shot  more  than  the 
pointed  one,  because  the  former  will  glance,  while  the  latter  digs  in  its 
point  and  then  turns  at  right  angles  to  the  target.  This  was  well  shown 
on  Thursday  last,  when  an  8-inch  shell  from  a  converted  Palliser  gun 
pierced  the  Warrior  target  at  an  angle  of  about  26  degrees,  the  weight 
of  the  shell  being  180  pounds,  that  of  the  charge  22  pounds.  We  hope 
that  many  interesting  experiments  will  yet  be  made  with  the  American 
gun,  and  we  sincerely  congratulate  Major  Rodman  on  the  excellence  of 
his  cast-iron,  while  we  still  adhere  by  preference  to  our  own  material, 
which  is  still  stronger,  especially  for  rifled  guns,  because  grooves  in  a 
gun  cast  on  Rodman's  method  would  vitally  affect  its  strongest  part, 
the  interior.  Let  us  pay  every  respect  to  a  very  formidable  weapon, 
but  we  can  do  so  without  crying  down  our  own  lighter  but  even  more 
destructive  ordnance.  We  cannot  admit  100  pounds  to  be  a  service 
charge  till  the  American  War  Office  gives  us  a  right  to  do  so,  and  if  the 
15  inch  gun  is  to  be  compared  with  our  9-inch,  and  exceptional  charges 
are  to  be  burnt  in  the  former,  we  can  hardly  be  denied  the  right  to  put 
a  little  extra  powder  into  the  latter.  The  15-inch,  with  its  service-batter- 
ing charge,  fails  to  penetrate  the  target  which  is  pierced  by  the  9-inch 
with  such  a  charge  that  several  hundred  rounds  can  be  fired  without 
destroying  the  gun. 

From  the  roar  of  the  Rodman  to  the  tiny  ringing  voice  of  the  mountain 
gun  is  a  great  downward  jump,  but  the  little  steel  piece  is  soon  to  do  its 
duty  in  actual  war,  unless  wise  and  peaceful  counsels  prevail  at  last  in 
Abyssinia.  Steel,  while  treacherous  in  large  masses,  from  the  difficulty 
of  casting  and  working  it  equally,  is  a  perfect  though  rather  expensive 
material  for  small  guns,  and  has  been  wisely  chosen  for  mountain  service. 
The  carriage  is  also  of  steel,  except  the  wheels,  and  nothing  could  be 
simpler  than  its  general  construction.  It  stood  the  force  of  recoil  very 


200          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

well  generally,  though  the  wheels  suffered  a  little  from  the  recoil  of  the 
piece  when  fired  at  high  angles  of  elevation.  This  niite  of  a  gun,  which 
a  man  might  easily  carry  in  his  arms,  for  it  weighs  only  150  pounds,  sent 
its  pretty  little  7-pound  projectile  2,944  yards,  or  more  than  a  mile  and 
two-thirds,  with  a  charge  of  6  ounces  of  powder  and  an  elevation  of  32 
degrees.  Such  long  range  work  is  not,  however,  likely  to  be  required  of 
it,  but  rather  shrapnel  practice  at  ranges  up  to  1,000  yards  or  less.  At 
500,  520,  and  540  yards  more  than  half  the  bullets  in  the  shrapnel  shell 
struck  a  target  representing  a  column  of  men.  With  half  an  ounce  of 
powder  and  the  same  elevation  the  projectile  ranged  478  yards.  The 
recoil,  which  was  very  lively  when  full  charges  were  used,  was  brought 
under  control  by  hobbling  the  carriage,  a  small  rope  being  fixed  from 
the  point  of  the  trail  to  one  of  the  wheel  spokes. 

The  so-called  64-pounder  gun,  converted  on  Palliser's  principle,  proved 
its  value  by  sending  its  shells  through  the  Warrior  plates,  breaking  once 
out  of  three  rounds  through  the  skin  and  setting  the  wooden  backing  on 
fire.  The  charge  was  1C  pounds,  range  500  yards.  The  8-inch  converted 
gun  did  even  more  work  at  70  yards  range,  at  an  angle  of  about  26 
degrees  to  the  face  of  the  target.  The  first  round  at  30  degrees  angle 
set  the  target  on  fire,  the  second  at  nearly  26  degrees  passed  through  all, 
bursting  just  as  it  cleared  the  inner  skin.  Here  are  three  instances  of 
the  value  of  rifled  guns.  Shell-fire  either  penetrates  the  target  opposed 
to  these  comparatively  light  pieces,  or  sets  the  backing  in  flames. 

Let  us  once  more  put  the  state  of  the  case  before  our  readers.  The 
smooth-bored  gun,  with  its  service-battering  charge,  and  an  expensive 
steel  shot,  fails  to  damage  seriously  a  target  which  the  rifled  gun,  less 
than  tAvo-thirds  the  weight  of  its  antagonist,  penetrates  with  shells  of  a 
cheaper  material.  With  an  increased  but  dangerous  charge  the  smooth- 
bore will  probably  penetrate  the  target  with  shot  but  never  with  shell. 
The  rifled  gun  can  be  used  in  broadsides,  the  smooth -bore  only  in  turrets. 
Given  the  same  weight  of  rifled  gun,  the  effect  will  be  much  greater.  If 
the  material  of  which  the  guns  are  made  be  compared,  we  take  the  actual 
results  obtained  at  Charleston,  and  fearlessly  assert  the  superior 
strength  of  our  ordnance,  for  the  federal  rifled  pieces  were  declared  by 
General  Gillinore  to  be  unable  to  fire  500  rounds  with  charges  of  only 
one- tenth  the  weight  of  the  projectile.  Our  9-inch  rifled  guns  outlive 
many  more  than  500  rounds  with  charges  of  about  one-sixth  the  shot's 
or  shell's  weight.  These  are  not  theories  but  facts,  and  if  any  opposing 
facts  can  be  urged  in  contradiction  they  are  at  least  out  of  the  bounds 
of  our  present  experience,  and  we  shall  be  glad  to  hear  them. 

Such  is  the  comparative  power  of  the  two  systems  of  ordnance.  The 
positive  power  of  the  Kodman  with  the  power  lately  fired  is  as  follows: 
With  50  pounds  of  powder  its  power  is  very  low  compared  with  its  weight. 
With  100  pounds  it  can  penetrate  the  sides  of  any  ship  afloat  in  the 
English  navy,  and  the  8-inch  target  at  70  yards,  the  shot's  energy  being 
about  153  tons  per  inch  of  circumference.  This  supposes  that  the  pro- 
jectile is  of  steel.  Cast-iron  may  or  may  not  break  up  according  to  its 
quality.  At  700  yards  it  would  pierce  the  Warrior,  Lord  Warden,  or 
Bellerophon,  but  probably  not  the  8-inch  target,  certainly  not  the  Her- 
cules or  Monarch,  now  on  the  stocks.  Its  powers  at  700  yards  are  much 
inferior  to  the  13-inch  rifled  gun  with  100  pounds  of  English  powder  at 
the  same  range,  the  difference  being  about  56  foot  tons  per  inch  of  circum- 
ference. At  no  range  whatever  would  the  American  gun  with  100  pounds 
charge  perforate  the  side  of  the  Hercules.  These  calculations  are  based 
upon  Captain  Noble's  formula,  (which  is  in  use  in  other  countries  besides 
England,  Prussia  for  instance,)  and  upon  the  known  strength  of  the 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  201 

English  targets.  To  complete  the  interest  of  the  late  experiments  it 
would  be  well  that  the  select  committee  should  try  targets  on  the  Ameri- 
can system  and  one  of  Krupp's  heavy  guns. 

RIFLED   GUNS. 

Extracts  from  the  report  of  the  Joint  Committee  on  the  Conduct  of  the  War. 

The  proportion  of  rifle  guns  to  those  with  smooth-bores  used  in  the 
navy  is  much  smaller  than  those  used  in  the  army.  The  difficulty  of 
obtaining  accuracy  of  fire  upon  a  vessel  in  motion  renders  the  rifled  guns 
less  efficient  Avhen  used  at  sea  than  when  used  upon  land. 

The  projectile  from  a  smooth-bore,  except  within  point-blank  range,  is 
fired  so  as  to  ricochet  upon  the  water,  arid  it  continues  its  flight  in  a 
straight  line  until  it  stops.  The  projectile  from  a  rifled  gun,  when  it 
strikes  the  water,  ricochets  at  an  angle  from  the  direct  line,  sometimes 

almost  at  right  angles,  and  it  is  therefore  less  reliable  at  long  range. 

******* 

The  rifled  gun  of  large  calibre,  employed  almost  wholly  in  the  army 
and  naval  service,  is  the  gun  invented  by  Robert  0.  Parrott.  It  is  com- 
posed of  a  cast-iron  cylinder  with  a  wrought-iron  jacket  or  band  shrunk 
upon  the  breech  of  the  gun  in  order  to  strengthen  it  about  the  seat  of 
discharge.  The  cast-iron  cylinder  of  this  gun  was  formerly  cast  solid, 
and  then  bored  out ;  but  latterly  those  of  the  largest  calibre  are  cast 

upon  the  Eodnian  principle. 

*  *      ,         *  *  *  *  * 

But  the  bursting  of  the  Parrott  guns  of  large  calibre,  together  with 
the  bursting  of  some  of  the  cast-iron  guns  of  large  calibre,  upon  the 
vessels  engaged  in  operations  against  the  defences  of  Charleston  and 
against  Fort  Fisher,  has  tended  to  weaken  confidence  in  the  durability 
of  those  guns,  and  would  seem  to  show  the  necessity  of  obtaining,  if 
possible,  some  other  gun  which  can  be  more  implicitly  relied  upon.  It 
is  the  testimony  of  our  officers  of  the  navy  that  the  bursting  of  one  gun 
in  a  fleet  tends  to  demoralize  the  crew  of  each  vessel  upon  which  a  gun 
of  that  kind  is  used,  whether  it  burst  or  not.  And  it  is  asserted  that 
the  loss  sustained  by  the  bursting  of  guns  of  large  calibre  on  vessels 
operating  against  Fort  Fisher  was  much  greater  than  the  loss  sustained 

on  the  entire  fleet  from  the  fire  of  the  enemy. 

******* 

In  view  of  these  considerations,  your  committee  desire  to  refer  some- 
what at  length  to  a  wrought-iron  gun  which,  to  them,  seems  to  possess 
those  qualities  ot  strength,  durability,  and  safety  which  are  so  very  de- 
sirable. It  is  the  invention  of  Horatio  Ames.  But  few  of  these  have 
yet  been  manufactured,  yet  they  have  successfully  withstood  every  test 
that  has  been  applied  to  them. 

Upon  the  21st  of  August  last,  at  the  request  of  the  inventor,  the  Presi- 
dent ordered  the  appointment  of  a  board  to  test  a  gun  of  7-inch  calibre 

manufactured  by  Mr.  Ames. 

******* 

As  the  result  of  the  examination  the  board  report : 

It  is  the  unanimous  opinion  of  the  board  that  Ames's  wrought-iron  guns  possess,  to  a 
degree  never  before  equalled  by  any  cannon  of  equal  weight  offered  to  our  service,  the  essen- 
tial qualities  of  great  lateral  and  longitudinal  strength,  and  great  powers  of  endurance  under 
heavy  charges  ;  that  they  are  not  liable  to  burst  explosively  and  without  warning,  even  when 
fired  under  very  high  charges;  and  that  they  are  well  adapted  to  the  wants  of  the  service 
generally,  but  especially  whenever  long  ranges  and  high  velocities  are  required.  It  is  also 
the  unanimous  opinion  of  the  board  that  Ames's  7-inch  guns,  of  which  he  has  now  15  nearly 
finished,  possess  sufficient  weight  and  strength  to  receive  an  8-inch  bore  and  even  greater, 
although  not  heavy  enough  for  a  10-inch  bore. 


202          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

The  opinion  of  Mr.  Fox,  the  Assistant  Secretary  of  the  Navy,  of  the  Ames's  gun,  and  of 
the  necessity  for  some  gun  of  that  character,  is  thus  stated  by  him  in  his  testimony : 

"I  think  it  is  a  fair  inference,  from  the  experience  we  have  had  with  the  small  guns  and 
100-pounders  which  he  (Mr.  Ames)  has  made,  that  he  has  the  correct  principle  of  manufac- 
ture, and  that  guns  manufactured  by  his  method  will  bear  any  amount  of  charge  that  can  be 
consumed  in  the  gun.  * 

"My  opinion  is  that  we  have  got  to  come  to  wrought-iron  or  steel  guns  and  abandon  cast 
iron." 

********* 

Extracts  from  the  testimony  of  Brigadier  General  George  D.  Ramsay  before 
the  Joint  Committee  on  the  Conduct  of  the  War. 

It  may  be  said  of  the  rifled  guns  that  we  were  called  upon  to  intro- 
duce the  rifled  system  in  time  of  war,  suddenly  and  without  the  facilities 
for  practical  experiment.  We  have  no  government  arsenal,  or  conve- 
nient place  adequate  to  proper  trials  for  range,  penetration,  &c.  There 
is  no  place  that  I  am  aware  of,  under  our  control,  for  extensive  land 
range,  and  for  that  reason  my  predecessor  recommended,  at  the  last 
session  of  Congress,  the  purchase  of  a  tract  of  land  near  New  York,  on 
the  New  Jersey  marshes,  for  this  purpose,  and  which  presented  an 
uninterrupted  and  secure  range  of  several  miles.  We  have  had  a  good 
deal  of  practice  with  field  and  the  4  J- inch  rifle  guns  at  the  Washington 
arsenal,  but  necessarily  over  the  water,  rendering  the  experiments 
unsatisfactory  both  as  to  ascertaining  penetration,  correctness  of  flight, 
&c.,  of  the  projectiles,  and  of  many  other  elements  necessary  in  judging 
of  what  constitutes  a  good  rifle  gun  and  a  good  projectile. 

Q.  Then  you  do  not  give  any  preference  to  the  Rodman  gun  over  the 
Parrott  gun,  but  are  getting  both  as  fast  as  you  can  f 

A.  No  preference  in  orders  given  for  guns  is  shown.  We  have  been 
and  are  getting  both  kinds  as  fast  as  we  can.  Unlimited  orders  have 
been  given  to  all  the  founders  making  guns.  The  entire  capacity  of 
the  country  has  been  called  into  requisition  to  meet  the  demands  of  the 
service.  Everything  has  been  done  on  the  part  of  the  government,  so 
far  as  I  am  advised. 

Q.  What  proportion  of  our  sea  and  land  armament  is  of  rifled  ordnance, 
and  when  were  rifled  guns  introduced  into  service  I 

A.  I  should  have  to  refer  to  the  records  to  answer  the  first  part  of 
your  question  ;  as  to  the  introduction  of  rifled  ordnance,  my  first  recol- 
lection of  them  was  at  the  battle  of  Bull  Run. 

Q.  What  proportion  of  the  land  ordnance  is  rifled,  so  far  as  you 
know? 

Q.  With  regard  to  the  old  guns  forming  a  portion  of  the  armament  of 
the  fortification,  we  are  now  rifling  every  gun  along  the  seaboard. 
We  are  at  this  very  moment  rifling  the  guns  at  Portland,  Portsmouth, 
and  Boston.  The  24  and  32-pounders  are  simply  rifled  ;  but  to  the  42- 
pounders  we  are  applying  the  wrought-iron  jacket  in  addition  upon  the 
Parrott  principle,  with  the  Parrott  increasing  twist.  Experiments  have 
shown  that  the  24  and  32-pounders  have  sufficient  endurance  without 
going  to  the  expense  of  banding. 

Q.  The  intention  is  to  have  all  the  guns  rifled  ? 

A.  Yes ;  the  old  guns,  to  include  the  42-pounders,  not  the  Rodmans. 
Some  of  them,  the  8  and  12-inch,  have  been  rifled  for  experiment. 

Q.  Does  it  not  weaken  ordnance  to  some  extent  to  rifle  it  ? 

A.  Yes;  to  some  extent;  but  we  are  enabled  to  make  reliable  rifled 
guns,  even  from  those  originally  smooth-bore,  as,  for  example,  a  third 
class  32-pounder  gun,  rifled  by  Captain  Parrott,  and  fired  with  his  own 
projectile,  64  pounds  (double  the  weight  of  the  32-pound  ball)  and  with 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          203 

six  pounds  of  powder,  withstood  1,000  rounds.  This  gun  was  not 
banded ;  its  tenacity  was  not  more  than  16,000  or  20,000,  the  standard 
being  about  30,000  pounds.  It  is  doubtful  whether  this  gun,  before 
being  rifled,  would  have  shown  greater  endurance  with  its  own  proper 
service  charge  with  round  ball.  We  consider  a  gun  a  good  gun  that 
will  stand  1,000  rounds. 

Q.  At  what  time  did  these  rifled  guns  come  into  use  I 

A.  We  had  several  batteries  at  the  first  battle  of  Bull  Eun ;  and  have 
since  then  furnished  them,  with  all  the  rapidity  that  the  foundries  could 
supply  them.  We  have  taken  all  the  smooth-bore  guns  out  of  the  field, 
and  substituted  rifled  guns  as  fast  as  we  could  get  them.  At  the  battle 
of  Bull  Eun  we  had  a  2T4^-inch,  that  is,  a  10-pounder  battery,  a  20-pounder 
battery,  and  one  30-pounder  gun,  which  was  lost. 

Q.  Can  you  give  us  any  description  of  what  is  called  the  Whitworth 
gun — an  English  gun? 

A.  The  Whitworth  gun  is  a  wrought-iron  rifled  breech -loading  gun. 
It  has  a  hexagonal  bore.  It  is  a  very  ingenious  and  beautifully  made 
gun.  It  is  liable  to  get  out  of  working  order  in  its  breech  arrangements 
from  the  peculiar  construction  of  the  screw,  which  requires  very  perfect 
mechanism.  This  screw  arrangement  becomes  foul  by  escape  of  gas, 
and  it  is  sometimes  difficult  to  close  the  breech.  There  are  also  muzzle- 
loading  Whitworth  guns. 

Q.  And  the  heating  of  the  gun  by  firing  would  effect  it,  I  suppose? 

A.  Of  course.  In  the  models  all  the  breech-loading  guns  seem  to 
work  very  well ;  but  when  you  apply  the  principle  to  large  masses  of 
metal  it  becomes  difficult  to  make  the  parts  work  easily. 

Q.  What  about  the  Blakely  gun  ? 

A.  That  is  made  a  little  after  the  manner  of  the  Parrott  gun.  I  think 
it  has  a  jacket  of  wrought  iron  shrunk  on  it,  commencing  at  the  trunnions 
and  embracing  the  entire  rear  of  the  gun. 

BURSTING  OF  PARROTT  GUNS. — REPLY  OF  MR.  WIARD  TO  MR.  PAR- 
ROTT. 

From  the  New  York  Evening  Post,  February  2,  1865. 

To  the  Editors  of  the  Evening  Post  : 

The  letter  of  Mr.  Parrott,  in  your  issue  of  Saturday  last,  seems  to  me 
to  be  an  effort  to  resuscitate  confidence  in  guns  and  theories  now  ex- 
ploded. Mr.  Parrott  attributes  the  bursting  of  his  guns  to  the  prema- 
ture explosion  of  shells  within  the  bore.  Why  does  he  not  show  this  to 
be  the  cause  by  a  series  of  experiments,  by  bursting  shells  in  the  bore  ? 
I  assert  that  he  cannot  burst  even  a  30-pounder  in  that  manner,  and 
that  a  300-pounder  can  be  so  burst  is  even  more  improbable,  except 
the  gun  has  been  heated  inside  by  a  succession  of  discharges  fired 
as  rapidly  as  guns  must  be  in  the  excitement  and  hurry  of  hot  bat- 
tle, where  the  duty  of  the  gun  is  quite  different  from  the  "  dress  parade" 
practice  of  the  proving  ground,  where  the  greatest  deliberation  is  the 
rule.  When  large  guns  are  fired  rapidly  the  inner  metal  along  the  bore 
is  expanded  in  all  directions  by  the  successive  increments  of  heat  from 
the  flame  of  powder  supplied  at  each  discharge  more  rapidly  than  it  can 
be  dispersed  throughout  the  whole  mass  of  metal  in  the  gun  or  radiated 
away  from  the  surface  of  the  bore ;  the  interior  swells  with  exactly  the 
force  it  would  exhibit  to  resist  compression,  straining  the  outside  metal 
to  the  extreme  verge  of  its  power  to  resist  fracture.  When  in  this  state, 
the  explosion  of  the  charge,  the  premature  explosion  of  the  shell,  the 
effort  of  the  gun  to  divert  the  shot  or  shell  as  it  recoils  backward  (the 


204          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

gun  being  elevated)  on  a  plane  different  from  the  plane  of  the  axis  of 
the  bore  or  the  direction  of  the  shot,  having  the  tendency  to  throw  the 
shot  higher  than  it  was  aimed,  or  to  depress  the  muzzle  of  the  gun, 
sometimes  breaks  the  muzzle  off  as  by  the  blow  of  a  heavy  sledge,  the 
gun  being  in  a  state  of  initial  strain,  may  cause  the  fracture. 

Mr.  Parrott  cannot  account  for  the  transverse  fracture  under  the  band 
by  the  explosion  of  shells  in  the  .bore.  A  15-inch  Rodman  gun,  cast 
hollow,  and -cooled  from  the  interior  to  get  initial  tension,  at  Pittsburg, 
a  few  months  since,  when  nearly  cold  and  ready  to  be  removed  from  the 
pit,  split  from  end  to  end.  The  inner  metal  had  been  cooled  by  water 
passing  through  the  bore,  while  the  outside  metal  retained  a  higher 
temperature.  The  outside  metal,  cooled  at  a  later  time,  shrunk  upon 
the  inner  metal  like  the  tire  upon  a  wagon  wheel.  The  cast  block  was 
about  16  feet  in  length,  and  the  wall  about  16  inches  in  thickness  ;  con- 
sequently, the  area  of  cross  section  ruptured  was  equal  to  3,172  inches. 
If  the  tensile  strength  of  the  metal  was  30,000  pounds  to  the  square  inch 
of  section,  the  pressure  bearing  upon  the  inner  metal  was  about  95,000,000 
of  pounds  on  each  side,  or  a  whole  tension  of  190,000,000  of  pounds. 

I  frequently  experiment  with  glass  models  of  guns,  which  I  have  sub- 
jected to  a  water  pressure  of  800  pounds  to  the  inch  of  surface  in  the 
bore.  These  are  broken  in  many  pieces  by  inserting  a  heated  rod  of  iron 
smaller  than  the  bore  in  such  a  manner  as  not  to  touch  the  surface. 

The  great  Mallet  mortar,  made  of  a  series  of  rings  held  together  by 
six  strong  bolts,  was  disabled  by  the  lengthwise  expansion  of  the  rings 
breaking  the  bolts. 

One  of  Blakely's  guns,  made  with  four  bolts  reaching  from  the  trun- 
nion ring  to  the  cascabel,  broke  the  bolts  in  the  same  manner.* 

The  inner  tube  of  the  Whitworth  gun,  shown  in  General  Gillmore's 
report,  increased  in  length  by  the  heat  communicated  to  xit,  and  closed 
the  vent,  being  shown  projecting  one  inch.t  If  the  bands  had  been 
fastened  by  screw-threads,  as  proposed  by  Professor  Treadwell,  and 
recommended  by  General  Gillmore  in  his  book  for  the  bands  of  the  Par- 
rott gun,  it  would  not  be  an  improvement  ;  the  bands  would  part  trans- 
versely as  did  the  breech  of  a  300-pounder  Armstrong  gun,  in  which  the 
breecii-piece  was  inserted  by  screw-threads  within  the  principal  rein- 
force band  abutting  against  the  inner  tube  of  steel,  it  was  burst  by 
the  lengthwise  expansion  of  the  inner  tube,  pushing  out  the  whole 
breech,  breaking  the  reinforce  band  transversely!.  Compare  this  ex- 
ample with  the  Whitworth  gun  shown  in  General  Gillmore's  report, 
and  with  those  Parrotts  that  have  failed  at  the  breech,  and  see  the 
analogy. 

The  bursting  of  Parrott  guns  has  also  been  attributed  to  the  fail- 
ure of  the  gunners  to  put  the  shot  home.  Colonel  Rodman  shows,  by  a 
series  of  experiments  by  firing  charges  of  powder  in  a  shell,  §  the  heaviest 
of  which  only  half  filled  the  chamber,  that  the  greater  the  proportion  of 
volume  of  space  to  the  volume  of  the  charge,  the  less  the  destructive 
effect  upon  the  walls.  And  even  if  the  effect  of  the  vis  viva  of  the  gases 
against  the  shot  and  the  wall  of  the  gun  immediately  behind  the  shot 
were  greater  than  the  effect  of  the  pressure,  it  would  not  account  for 
the  transverse  fracture  or  the  blowing  out  of  the  breech;  neither  can 

*At  this  round  the  four  bolts  gave  way— the  four  united  being  equal  to  a  solid  bar  the 
size  of  the  bore.  The  rest  of  the  gun  was  uninjured.  *  *  *  I  had  this  gun  re-made, 
with  four  bolts  of  the  best  charcoal  iron,  but  they,  too,  broke  without  injury  to  the  tubular 
part.  —  Paper  read  by  Captain  Blakelcy  before  the  United  Service  Institution,  England;  vol. 
Ill,  Journal. 

t  See  Plate  X,  Fig.  1 

t  See  Plate  X,  Figs.  3  and  4. 

$  See  Plate  VIII. 


EXPERIMENTS  ON  HEAVY  OEDNANCE.          205 

this  particular  fracture  be  accounted  for  by  the  sand  getting  into  the 
bore,  as  in  General  Gillmore's  practice  on  Morris  island.  For  the  same 
reason,  if  the  shot  is  projected  toward  the  muzzle  its  vis  viva  cannot  be 
expended  upon  the  breech.  If  the  theory  of  unequal  expansion  from  the 
heat  of  firing  is  accepted,  it  completely  explains  all  the  phenomena,  but 
it  also  has  this  other  effect — it  brings  us  to  the  conclusion  that  all  our 
guns  have  been  erroneously  made  $  for  if  we  fabricate  a  gun  in  the  best 
manner  to  resist  the  pressure  of  the  powder,  i.  e.,  with  initial  tension,  it 
is  in  the  worst  state  to  withstand  the  unequal  expansion.  In  1862  I 
advanced  the  same  views  I  am  herein  advocating,  but  they  interfered 
with  the  patented  plans  of  ordnance  officers  or  others  in  intimate  rela- 
tions with  our  ordnance  department,  charged  with  the  duty  of  procur- 
ing all  the  guns  of  government,  and  hence  have  never  received  the 
attention  they  deserve.  I  foretold  that  our  guns  would  fail  whenever 
they  "  received  a  fair  and  regular  trial  of  their  powers  of  resistance  to 
the  proper  strains  of  actual  service,"  which  Mr.  Parrott  indicates  very 
strongly  they  have  not  yet  been  subjected  to. 

For  guns  that  would  smash  "  British  and  French  iron-clads  into  eter- 
nal smithereens,"  or  annihilate  Charleston,  our  foolish  and  fond  people, 
the  tax-payers,  would  be  willing  to  pay  the  hundreds  of  millions  charged 
to  them,  on  that  account. 

It  should  be  recollected  that  we  have,  perhaps,  eighty  heavy  guns 
(mounted  in  turrets)  of  which  the  carriages — "  for  what  is  a  ship  but  a 
gun-carriage  ?"  says  Admiral  Dahlgren — have  cost  about  one  million  of 
dollars  each,  and  these  guns  are  ordinarily  capable  of  being  fired  only 
once  in  fifteen  minutes  each,  except  as  at  the  bombardment  of  Fort 
Fisher,  (where  two  out  of  eight  failed  from  rapid  firing — fired  on  that 
occasion  one  shot  in  three  minutes  from  each  gun.)  The  whole  fleet  of 
turret  iron-clads,  during  a  bombardment,  can  at  this  rate  fire  but  about 
five  shots  a  minute. 

The  Minnesota,  it  is  said,  can  fire  a  shot  from  her  fifty-two  guns  in 
every  thirty  seconds  of  time  each — about  one  hundred  shots  per  minute, 
equal  to  five  whole  fleets  of  iron  dads.  , 

The  guns  of  our  iron-clads  have  been  long  in  service,  and  what  have 
they  done  ?  One  shot  struck  the  pilot  house  of  the  Atlanta,  doing  some 
damage ;  one  struck  the  stern  of  the  Tennessee,  but  did  not  penetrate. 
Where  is  the  record  of  any  other  service  ?  We  know  that  Fort  Mc- 
Allister was  bombarded  eight  hours,  inflicting  but  little  injury  to  the 
works ;  and  in  an  attack  on  Fort  Sumter  by  nine  iron-clads,  last- 
ing forty  minutes,  five  of  the  nine  were  disabled.  Our  forces  on  Morris 
island  were  balked  of  success  for  a  whole  campaign,  under  the  skilful 
and  brave  General  Gillmore,  for  the  want  of  guns  ;  23*  of  those  Parrott 
bombards  burst  in  the  action ;  and  who  will  attribute  the  want  of  success 
to  any  other  cause?  Yet  Mr.  Parrott  writes  you,  regretting  that  Gen- 
eral Gillmore  "  should  undertake  to  assign  limit  to  the  endurance  of  his 
guns."  The  last  paragraph  of  Mr.  Parrott's  letter  is  most  significant. 
He  says,  "  I  well  know  that  nothing  stands  in  the  way  of  real  improve 
ment,  so  much  as  attributing  failures  to  a  wrong  cause."  If  "  consid- 
erations far  beyond  the  interests  or  feelings  of  an  individual"  influence 
him,  let  him  now  heartily  assist  the  good  work  of  opening  up  the  busi- 
ness of  inventing  and  fabricating  guns  to  outsiders,  and  no  longer  be 
connected  with  that  close  corporation,  the  regulars,  more  familiarly 
known  by  the  soubriquet  u  West  Point." 
Eespectfully, 

NOEMAK  WIAED. 

WASHINGTON,  January  30, 1865. 

*  It  has  since  been  found  out  that  more  than  50  of  this  kind  of  guns  burst  on  Morris  Island. 


206 


EXPERIMENTS    ON    HEAVY    ORDNANCE. 


RELATIVE  POWER  OF  ENGLISH  AND  AMERICAN  GUNS. 

[From  the  report  of  Captain  R.  H.  Noble,  royal  artillery,  to  the  ordnance  select  committee, 
dated  Woolwich,  England,  27th  August,  1866.] 

Table  giving  the  remaining  velocities  and  "work"  of  spherical  steel  solid  shot 
fired  from  15-inch  and  11-inch  guns. 


Gun. 

Charge. 

Projectile. 

Initial  velocity. 

At  200  yards. 

At  500  yards. 

At  1,000  yards. 

s 

tf 

I 

Q 

Remaining 
velocity. 

> 

Remaining 
velocity. 

cs 
>. 

bo 

S    f^ 

'a  .-S 
|| 

Vis  viva. 

Lbs. 

Lbs. 

Inches. 

Feet. 

Feet. 

Tons. 

Feet. 

Tons. 

Feet. 

Tons. 

15-inch  
11-inch 

50 
20 

484 
189 

14.85 
10.85 

1,070 
1,080 

1,028 
1,019 

3,547 

1,361 

969 
936 

3,152 
1,148 

880 
818 

2,599 

877 

From  this  table  we  can  approximately  determine  the  effect  of  15  -inch 
and  11-inch  steel  projectiles. 

Thus,  assuming  that  the  penetration*  varies  universally  as  the  diame- 
ter, and  that  it  requires  2,642  tons  of  "work"  on  impact  to  send  a  steel 
shot  of  9".  14  through  the  side  of  the  Lord  Warden,  the  penetration  of  a 
steel  shot  from  the  15-inch  gun  will  require  a  force  represented  by  the 
following  proportion  : 

9.14  :  2,642  ::  14.85  :  x  and  x  =  4,292  tons. 

It  would,  therefore,  require  a  force  of  4,292  tons  to  send  a  steel  shot 
14.85  inches  diameter  through  the  Lord  Warden. 

A  glance  at  the  last  table  shows  that  the  15-inch  gun  is  unable  to 
accomplish  this  even  at  a  range  of  200  yards,  and  it  is  further  very  doubt- 
ful whether  this  gun,  fired  with  50  pounds  of  powder,  which  is  as  heavy 
a  charge  as  it  will  stand,  and  a  solid  steel  shot  of  484  pounds,  w^ould  pene- 
trate the  side  of  the  iron-clad  ship  Lord  Warden,  even  were  the  muzzle  of 
the  gun  touching  the  armor  plates  of  the  vessel. 

It  is  needless  to  remark  that  the  11-inch  gun  would  be  much  less 
effective.  These  conclusions  go  to  prove  — 

1st.  That  the  7-inch  muzzle-loading  rifled  gun  of  134  hundred  weight, 
fired  with  a  solid  elongated  steel  shot  of  100  pounds,  and  charge  of  25 
pounds,  is  not  capable  of  piercing  the  Lord  Warden  at  any  range. 

2d.  The  same  remark  applies  to  the  100-pounder  smooth-bore  gun  with 
a  spherical  steel  shot  of  104  pounds  and  25  pounds  charge. 

3d.  The  9.22-inch  rifled  gun  of  12  tons,  fired  with  an  elongated  steel 
shot  of  221  pounds  and  44  pounds  charge,  is  capable  of  piercing  the  Lord 
Warden  up  to  a  range  of  about  1,000  yards. 

4th.  That  the  same  remark  applies  to  the  10.5-inch  gun  of  12  tons,  fired 

*  Vis  viva  has  been  given  in  foot-tons  instead  of  foot-poimds,  in  consequence  of  the  num- 
ber of  figures  required  to  express  the  latter. 
We2 


where  — 

W=  weight  of  shot. 
v   =  velocity  on  impact. 
g  =the  accelerating  force  of  gravity. 

By  penetration  is  meant  actual  perforation  through  the  plate,  or  the  power  of  passing 
through  the  plate.     In  the  case  of  penetration  into  iron  plates,  the  term  indent  has  been  used. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          207 

with  a  solid  elongated  shot  of  301  pounds  and  charge  of  45  pounds,  and 
to  the  present  9-inch  service  gun  of  12  tons. 

5th.  That  the  American  sniooth-bore  guns  of  15,  13,  11,  and  9-inch 
calibre,  fired  with  solid  spherical  steel  shot,  and  the  highest  charges 
which  they  will  bear  with  safety,  are  not  capable  of  piercing  the  Lord 
Warden  at  any  range  whatever. 

6th.  This  vessel  could  steam  past  batteries  armed  with  the  above 
smooth-bore  guns  without  suffering  except  from  "racking"  effect. 

THE  BELLEROPHON.   ' 

The  trial  of  this  target  was  of  such  an  undecided  character  and  of  such 
a  comparatively  mild  form  that  it  is  difficult  to  obtain  sufficient  data 
upon  which  to  base  any  comparison  between  this  vessel  and  other  iron- 
clads. The  most  severe  blow  it  encountered  was  from  the  10.5-inch  rifled 
gun  with  a  spherical  steel  shot  of  165  pounds  and  charge  of  35  pounds, 
the  striking  "work"  being  2,472  tons.  This  shot  failed  to  penetrate  the 
target,  but  we  have  no  evidence  to  prove  that  the  10.5-inch  gun  would 
not  have  penetrated  with  a  charge  of  50  pounds  and  striking  "work"  of 
2,898  tons. 

The  Bellerophon  is  undoubtedly  of  a  stronger  construction  than  the 
Warrior  and  Minotaur  class,  but  there  is  no  direct  evidence  to  prove  that 
it  is  as  strong  or  stronger  than  the  Lord  Warden. 

We  have  seen  that  75.4  foot-tons  per  inch  of  shot's  circumference  has 
failed  to  penetrate  the  Bellerophon,  but  it  appears  that  this  force  is  quite 
sufficient  to  penetrate  this  target  when  the  plates  are  5.5  inches  thick 
instead  of  6  inches  (rounds  949  to  952). 

W^e  have  no  evidence,  however,  whether  75  foot-tons  per  inch  may  not 
be  too  much  for  a  Bellerophon  with  5.5-inch  plates.  If  we  assume  that 
this  force  is  only  sufficient  for  the  penetration  of  5.5-inch  plates  on  a 
backing  and  skin  similar  to  the  Bellerophon,  the  latter  with  6-inch  plates 
would  require  a  force  of  89.6  foot-tons  per  inch,  which  is  about  what  is 
required  by  the  Lord  Warden. 

The  fact,  however,  of  the  10.5-inch  gun  having  failed  to  pierce  this 
target  indicates  that  the  American  smooth-bore  15  and  11-inch  guns 
fired  with  solid  steel  shot,  and  the  highest  charges  they  are  capable  of 
bearing  with  safety,  would  not  penetrate  it  at  any  distance  over  100 
yards.  This  vessel,  therefore,  could  pass  batteries  so  armed  without  suf- 
fering except  by  "  racking." 

THE  WARRIOR. 

We  see  from  the  table*  that  the  7-inch  rifled  gun  is  capable  of  piercing 
the  side  of  this  vessel  with  a  100  pounds  shot  and  20  pounds  charge,  the 
striking  "work"  being  1,374  tons,  (round  1,018). 

The  effect  of  the  100-pounder  gun  would  therefore  be  represented  by  the 
proportion — 

6.91  :  1,374  : :  8.87  :  a?,  and  x  ==  1,764. 

The  force,  therefore,  required  to  send  a  steel  shot  from  the  100-pounder 
gun  through  the  Warrior  would  be  about  1,764  tons,  and  we  may  assume 
that  any  force  under  this  would  not  produce  the  required  effect. 

Thus  we  find,  round  972,  that  a  shot  from  the  100-pcuuder  struck  the 
Warrior  with  a  force  of  1,573  tons,  but  failed  to  penetrate. 

*  Appendix,  page  38. 


208  -    EXPERIMENTS    ON    HEAVY    ORDNANCE. 

In  the  same  manner  we  can  approximate  to  the  force  required  to  send 
a  shot  from  the  9.22-inch  gun  through  the  Warrior — 
6.91  :  1,374  : :  9.14  :  x,  and  x  =  1,813  tons. 

The  9.22-inch  gun  could  therefore  send  a  steel  shot  through  the  War- 
rior, provided  the  striking  force  were  1,813  tons. 

If  the  shot,  therefore,  was  221  pounds  weight,  the  necessary  velocity 
would  be  1,087  feet,  and  if  the  gun  were  fired  with  its  full  charge  of  44 
pounds  it  would  send  an  elongated  steel  shot  of  221  pounds  through  the 
Warrior  at  about  2,000  yards  range.* 

In  the  same  manner,  in  the  case  of  the  10.5-inch  gun,  we  have  the  pro- 
portion— 

6.91  :  1,374  : :  10.43  :  a?,  and  x  —  2,074. 

The  10.5-inch  gun  would  therefore  send  its  shot  through  the  Warrior, 
provided  the  striking  force  were  2,074  tons. 

From  this  it  appears  that  the  Warrior  is  of  weaker  construction  than 
the  Lord  Warden,  as  the  10.5-inch  gun  failed  to  penetrate  the  latter  with 
a  striking  force  of  2,898  tons. 

In  the  case  of  the  15-inch  American  guns,  we  have  the  proportion — 
6.91  :  1,374  :  :  1,485  :  a?,  and  x  =  2,953  tons. 

From  Table  XII,  it  appears  that  the  15-inch  gun  fired  with  a  spherical 
steel  shot  of  484  pounds,  and  a  charge  of  50  pounds,  would  penetrate 
the  Warrior  at  any  distance  up  to  500  yards,  but  would  not  do  so  at 
1,000  yards. 

In  the  case  of  the  11-inch  gun  we  have — 

6.91  :  1,374  : :  10.85  :  x,  and  x  =  2,157. 

And  from  Table  XII,  we  find  that  the  11-inch  gun  fired  with  a  solid 
steel  shot  of  189  pounds  and  charge  of  20  pounds  would  not  penetrate 
the  Warrior  at  any  range,  not  even  if  the  muzzle  of  the  gun  were  touch- 
ing the  armor  plates. 

From  these  considerations  the  following  effects  are  probable: 

1.  The  7-inch  muzzle-loading  rifle  gun  of  130  hundred  weight,  with  a 
solid  shot  of  100  pounds,  and  charge  of  25  pounds,  is  capable  of  piercing 
the  side  of  the  Warrior  up  to  a  range  of  about  600  yards.t 

2.  The  100-pounder  smooth-bore  gun  (9-inch)  of  125  hundred  weight, 
with  a  solid  spherical  steel  shot  of  104  pounds  weight  and  25  pounds 
charge,  is  not  capable  of  piercing  the  Warrior  at  any  distance  over  100 
yards. 

3.  The  9.22-inch  rifled  gun  of  12  tons  with  a  solid  elongated  steel  shot 
of  221  pounds  and  charge  of  44  pounds  is  capable  of  piercing  the  War- 
rior up  to  a  range  of  2,000  yards. J 

4.  The  10.5-inch  rifled  gun  of  12  tons  with  a  solid  elongated  steel  shot 
of  301  pounds  and  charge  of  45  pounds  is  capable  of  piercing  the  War- 
rior up  to  a  range  of  2,000  yards. 

5.  The  American  15-inch  gun  of  22  tons  with  a  spherical  steel  shot  of 
484  pounds  and  charge  of  50  pounds  is  capable  of  piercing  the  Warrior 
up  to  a  range  of  500  yards. 

6.  The  American  smooth-bore  11-inch  and  9-inch  guns  fired  with  solid 
sperical  steel  shot  and  their  maximum  charges  are  not  capable  of  piercing 
the  Warrior  at  any  range. 

*  At  this  range  the  projectile  will  strike  at  a  certain  angle  corresponding  to  the  angle  of 
descent,  but  with  rifled  projectiles  this  angle  is  very  small,  and  may  practically  be  neglected. 

t  The  same  result  would  probably  occur  with  the  present  service  charge  for  this  gun,  viz. 
22  pounds,  and  shot  of  115  pounds 

t  The  same  result  would  occur  with  the  service  9-inch  gun  of  12  tons. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  209 

7.  This  vessel  could  pass  batteries  armed  with  15-inch  guns,  as  above, 
at  a  distance  of  800  yards,  without  suffering,  except  by  "racking." 

THE  MINOTAUR. 

This  class  differs  from  the  Warrior  in  having  one  inch  of  iron  armor 
plating  substituted  for  nine  inches  of  wood  backing. 

In  the  trial  of  this  target  an  experimental  powder  named  2  A  4  was 
made  use  of,  and  this  accounts  for  the  effects  observed  with  the  10.5-iiich 
gun. 

It  appears  from  Table  XIV  that  when  the  ordinary  service  powder 
was  used  the  result  was  something  the  same  as  in  the  case  of  the  Warrior. 
The  actual  strength  of  these  ships  may  therefore,  in  absence  of  direct 
evidence  to  the  contrary,  be  assumed  to  be  equal ;  but  whether  the  wood 
and  iron,  which,  combined,  form  the  mass  of  resistance,  have  been  more 
advantageously  distributed  in  the  construction  of  the  Warrior  than  in 
that  of  the  Minotaur,  is  a  separate  question. 

On  the  whole,  it  may  be  assumed  that  the  remarks  which  apply  to  the 
Warrior  are  equally  applicable  to  the  Minotaur  and  ships  of  her  class. 

THE   HERCULES. 

This  target  was  by  far  the  strongest  ever  tried  at  Shoeburyness,  and 
accordingly  it  received  the  most  severe  treatment.  The  preliminary 
experiments  were  made  with  the  9".22^  10".5,  and  10"  rifled  guns  of  12 
tons,  firing  solid  steel  shot  with  very  high  charges. 

It  appears  that  rounds  1041,  1045  penetrated  the  8-inch  plate,  and 
forced  the  pieces  into  the  12-inch  wood  backing.  Both  these  rounds 
struck  between  two  ribs ;  1045,  however,  met  with  more  resistance  than 
1041,  as  it  struck  just  over  one  of  the  horizontal  plates;  the  armor  plate 
was  thus  supported  in  rear  of  the  point  struck  by  a  rigid  backing.  An 
8-inch  plate  unbacked  requires  88.5  foot-tons  per  inch  of  shot's  circum- 
ference to  just  penetrate  it;*  it  was  to  be  expected,  therefore,  that  the 
above  rounds  should  do  so. 

Rounds  1043,  1C 44,  1040,  1042,  struck  the  9-inch  plate,  which,  if 
unbacked,  would  require  a  fore  of  112.1  foot-tons  per  inch  of  shot's  cir- 
cumference to  penetrate  it. 

Bound  1044  was  therefore  the  only  shot  which  had  sufficient  force  to 
penetrate  the  plate,  and  this  round  struck  both  on  a  rib,  and  full  on  one 
of  the  rigid  backings;  1040  almost  penetrated  the  plate,  as  although  the 
absolute  indent  was  only  4.5  inches  the  piece  of  plate  struck  was  almost 
dislodged;  1042  ought  to  have  done  more  damage  than  it  did;  probably 
the  steel  was  not  of  the  best  quality. 

The  target  was  subsequently  tested  by  firing  at  it  with  the  13-inch 
wrought-iron  gun  of  22  tons,  using  solid  steel  and  chilled  iron  shot  of 
570  pounds  with  100  pounds  of  powder. 

The  gun  was  at  700  yards  from  the  target.  > 

The  results  proved  that  the  target  was  impenetrable  when  struck  fair, 
although  it  was  penetrated  by  a  chilled  shot  which  struck  just  above  a 
previous  round.f 

When  it  is  considered  that  this  target  was  only  18.2  feet  x  8  feet  x  4 
feet,  and  that  it  received  blows  amounting  in  all  to  over  70,000  foot-tons, 
it  must  be  confessed  it  did  its  duty. 

*  With  a  hemispherical-headed  shot. 

t  It  is  probable  that  this  target  would  have  been  penetrated  had  the  steel  projectiles  been 
ogival-headed,  as  suggested  on  minute  lti,025. 

Rep.  Ko.  206 14 


210  EXPERIMENTS    ON    HEAVY    ORDNANCE. 


THE   SMALL   PLATE. 

This  target  represented  a  wooden  ship  armor-plated,  such  as  the 
French  Flandres,  &c. 

It  appears  that  this  class  of  iron-clad  is  not  quite  as  strong  as  that 
represented  by  the  Warrior  or  Minotaur,  which  are  iron  vessels  armor- 
plated,  and  of  course  not  nearly  as  strong  as  the  Lord  Warden  or  Bell- 
erophon. 

Thus  the  10.5-inch  gnu,  with  a  striking  "work"  of  1,657  tons,  pene- 
trated the  "small  plate'7  target;  and  we  have  seen  that  this  gun  would 
require  a  striking  force  of  2,047  tons  to  send  the  same  shot  through  the 
Warrior.  It  is  hardly  fair,  however,  to  take  this  round  (850)  for  the 
basis  of  a  comparison  with  other  guns,  as  it  appears  that  the  target  had 
been  previously  considerably  shaken. 

On  the  whole  it  may  be  assumed  that  vessels  of  the  class  represented 
by  the  "small plate"  target  are  something  weaker  than  those  represented 
by  the  Warrior,  and  that  the  remarks  which  apply  to  the  latter  are 
applicable  to  the  former  in  a  greater  degree.* 

THE   8-INCH   TARGET. 

This  target,  as  before  stated,  was  designed  for  the  trial  of  various 
descriptions  of  steel  and  chilled  iron  projectiles. 

The  guns  used  in  this  experiment  were  the  8  and  9-inch  muzzle-load- 
mg  Woolwich  rifled  guns  firing  service  charges. 

The  results  of  this  practice  are  fully  given  in  table  XIY,  in  the  appen 
dix,  and  may  be  briefly  summed  up  as  follows: 

1.  The  target  was  proof  against  all  projectiles  when  tired  at  obliquely. 

2.  The  target  was  not  penetrated  when  fired  at  direct,  except  by  the 
Falliser  chilled  projectile  having  a  head  struck  with  a  radius  of  L5 
diameters.    This  projectile  was  therefore  clearly  the  victor,  but  whether 
ihis  is  owing  to  its  being  in  the  form  of  a  shell  or  to  its  bursting  charge, 

ve  have  no  direct  results  to  show. 

3.  It  is  probable  that  had  the  wood  and  iron  which  compose  the  target 
been  differently  distributed  the  resistance  would  have  been  greater.     As, 
liowever,  the  target  was  built  for  a  special  purpose,  this  was  not  one  of 
the  conditions  to  be  fulfilled. 

4.  It  is  proved  that  a  pointed  projectile  of  7.92  inches  in  diameter 
can  cut  a  hole  in  an  8-inch  plate  provided  it  strike  with  the  necessary 
work . 

5.  As  a  rule  these  experiments  coincide  with  previous  trials,  with  the 
exception  of  the  Palliser  shell,  which  penetrated.    This  projectile  accom- 
plished more  than  calculation  would  lead  us  to  expect.    Some  further 
experiments  will  be  necessary  to  determine  the  value  of  fc  for  this  form 
of  head. 

The  following  table  shows  the  probable  distance  at  which  various 
guns,  firing  solid  steel  shot  with  full  service  charges,  would  penetrate 
iron-clad  ships  at  present  (1866)  in  the  service. 

*  This  target  is  of  equal  if  not  superior  strength  to  the  Warrior,  if  struck  on-the  5.9-inch 
plates. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  211 


APPENDIX  E. 

List  of  guns  burst  and  disabled  in  the  army  and  navy  since  1861;  preparal 
from  reports  and  evidence  before  the  Joint  Committee  on  Ordnance. 

Navy  Parrott  100  pounder  rifle  gun,  No.  2,  burst  at  the  muzzle  on  the 
steamer  Hunchback,  June  19,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  4,  burst  at  the  reinforce,  and 
through  the  band  in  several  places,  on  the  steamer  Westfield,  October 
31,  1862. 

Navy  Parrott  rifle  gun  100-pounder,  No.  6,  burst  at  muzzle  and  chase 
on  the  steamer  Mahaska,  1863. 

Navy  Parrott  100-pounder  gun.  No.  11,  burst  at  the  muzzle  on  the 
steamer  Commodore  Barney,  April  10,  1862. 

Navy  Parrott  100-pounder  rifle  gun,  No.  18,  cracked  in  rear  of  vent  or. 
the  steamer  Genesee,  May,  1864. 

Navy  Parrott  100-pounder  rifle  gun.  No.  21,  burst  at  muzzle  on  Cim- 
arroii,  February  15,  1864. 

Navy  Parrott  100  pounder  rifle  gun,  No.  24,  burst  from  trunnion  to 
rear  of  band  on  the  Paul  Jones,  July  18,  1863. 

Navy  Parrott  100-pounder  rifle  gun,  No.  25,  cracked  in  two  places  ar 
vent  on  Sassacus,  January,  1865. 

Navy  Parrott  100-pounder  rifle  gun,  No.  29,  burst  by  blowing  off  breech 
on  the  Juniata,  December  25,  1864. 

Navy  Parrott  100  pounder  rifle  gun,  No.  44,  burst  at  breech  on  Com- 
modore Perry,  June  17,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  135,  cracked  at  the  vent,  Forfc 
Jackson,  June  14,  1865. 

Navy  Parrott  gun  100-pounder;  No.  141,  burst  at  the  breech,  which 
was  blown  out  on  the  Mackinaw,  December  26,  1864. 

Navy  Parrott  gun  100-pounder,  No.  149,  cracked  at  the  top  of  the  bore 
and  around  the  breech  on  the  Commodore  Read,  November  14,  1864. 

A*rrny  Parrott  100-pounder  gun,  No.  1,*  burst  through  the  breech, 
band,  and  reinforce,  to  forward  of  the  trunnions,  on  the  revenue  steamer 
Naugatuck,  called  the  Stevens'  Battery,  in  the  James  river,  during  the 
attack  on  Fort  Darling,  May  15,  1862. 

Navy  Parrott  100-pounder  Parrott  gun,  No.  150,  cracked  at  the  venfc 
on  Commodore  Read,  November  14,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  162,  burst  at  the  muzzle  on 
the  Ticonderoga,  November  14,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  166,  burst  by  blowing  oft 
breech  off  Fort  Fisher  on  the  Yantic,  December  24,  1864. 

Navy  Parrott  100-pounder,  No.  194,  rifle,  cracked  through  the  vent 
on  the  Maumee,  June,  1865. 

Navy  Parrott  100-pounder  rifle  gun,  No.  213,  cracked  at  vent  on  the 
Kansas,  December  24,  1864. 

Navy  Parrott  gun,  100-pounder,  No.  233,  cracked  on  the  outside  from 
trunnion  to  band  on  the  Osceola,  June  15,  1865. 

Navy  Parrott  100-pounder  rifle  gun,  No.  238,  cracked  on  the  outside 
from  trunnion  to  band  on  the  Mendota,  July  24,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  262,  burst  at  muzzle  on  Talla- 
poosa,  April  5, 1865. 

Navy  Parrott  100-pounder  rifle  gun,  No.  283,  burst  on  the  Mohican, 
December,  1864. 

*  It  appears  that  this  gun,  although  the  first  of  its  class,  was  put  in  service  without  being- 
subjected  to  extreme  proof.  Its  failure  did  not  deter  the  ordnance  department  from  pur- 
chasing, subsequently,  a  large  number  of  similar  guns. 


212  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Navy  Parrott  100-pounder  rifle  gun,  No.  311,  burst  into  10  pieces  on 
the  Ticonderoga,  December  24, 1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  325,  cracked  through  vent 
on  the  Lenapee,  February,  1865. 

Navy  Parrott  100-pounder  rifle  gun,  No.  330,  cracked  through  vent 
on  Lenapee,  February,  1865. 

Army  Parrott  100-pounder  rifle  gun,  No.  104,  burst  on  Morris  island 
a  section  of  the  reinforce  thrown  off  in  front  of  the  band.  The  gun  burst 
at  the  216th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  21,  burst  by  throwing  off  a 
large  piece  of  the  reinforce  in  front  of  the  band  on  Morris  island  at  the 
1,150th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  158,  burst  on  Morris  island 
at  the  256th  round,  a  large  piece  of  reinforce  thrown  off  in  front  of  the 
band. 

Army  Parrott  100-pounder  rifle  gun,  No.  19,  burst  on  Morris  island  at 
the  128th  round  ;  a  large  piece  broken  off  in  front  of  band. 

Army  Parrott  100-pounder  rifle  gun,  No.  161,  burst  on  Morris  island  at 
the  377th  round ;  the  gun  burst  through  breech  and  the  band,  and  the  frac- 
ture extended  forward  in  front  of  trunnions. 

Army  Parrott  100-pounder  rifle  gun,  No.  53,  burst  on  Morris  island  at 
the  152d  round;  burst  through  breech,  band,  and  reinforce  to  forward 
of  trunnions. 

Army  Parrott  100  pounder  rifle  gun,  No.  157,  burst,  throwing  off  a 
large  piece  in  front  of  the  band,  at  the  219th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  153,  burst  forward  of  the 
band  and  to  the  chase  in  front  of  the  trunnions,  at  the  138th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  66,  burst  in  front  of  the  band, 
on  Morris  island,  at  the  331st  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  95,  burst  at  muzzle,  on  Mor- 
ris island,  at  the  87th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  736,  burst  through  band, 
breech,  and  reinforce,  to  forward  of  the  trunnions,  at  514th  round,  on 
Morris  island. 

Army  Parrott  100-pounder  rifle  gun,  No.  155,  burst  through  breech, 
band,  and  reinforce,  to  trunnions,  on  Morris  island,  at  126th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  97,  burst  through  breech, 
band,  and  reinforce,  forward  to  trunnions,  on  Morris  island,  at  the  439th 
round. 

Army  Parrott  100-pounder  rifle  gun,  No.  51,  burst  forward  of  the 
band,  beyond  the  trunnions,  nearly  half  the  length  of  the  chase,  on 
Morris  island,  at  the  214th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  154,  burst  by  blowing  off 
breech,  on  Morris  island,  at  the  38th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  66,  burst  in  front  of  the 
band,  forward  to  front  of  the  trunnion,  and  breech  blown  out,  on  Morris 
island,  May  9,  1864,  at  the  108th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  99,  cracked  on  outside  from 
band,  to  forward  of  trunnions,  at  6th  round  fired  on  Charleston,  May  15, 
1864. 

Army  Parrott  100-pouuder  rifle  gun,  No.  14,  burst  in  rear  of  trunnions 
into  eight  pieces,  and  band  into  two  pieces,  on  Morris  island,  May  19, 
1864,  at  1,100th  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  156,  burst  in  front  of  band, 
at  13th  round  fired  upon  Charleston,  May  27,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  100,  burst  in  front  of  band, 
on  Morris  island,  June  6,  1864,  at  226th  round. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  213 

Army  Parrott  100-pounder  rifle  gun,  No.  — ,  burst  in  front  of  band, 
on  Morris  island,  July  15,  1864,  at  491st  round. 

Army  Parrott  100-pounder  rifle  gun,  No.  23,  cracked    outside  from 
band  to  trunnions,  at  1,480th  round,  September  4,  1864. 
•    Army  Parrott  100-pounder  rifle  gun,  No.  187,  burst  through  breech 
and  reinforce,  at  316  rounds,  September  12,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  186,  burst  by  blowing  off 
breech,  at  31st  round,  September  13,  1864,  on  Morris  island. 

Army  Parrott  100-pounder  rifle  gun,  No.  162,  burst  into  a  large  num- 
ber of  pieces,  some  of  which  were  thrown  out  of  the  battery.  The  shell 
at  the  charge  which  burst  the  gun,  was  thrown  4rOOO  yards,  September 
17,  1864,  Morris  island. 

Navy  Parrott  100-pounder  rifle  gun,  No.  81,  burst  at  breech  and  re- 
inforce into  many  pieces,  some  of  which  were  thrown  a  great  distance. 
The  shell  at  time  of  bursting  (883d  round)  reached  Charleston  from  Mor- 
ris island. 

Navy  Parrott  100-pounder  rifle  gun,  No.  128,  burst  in  front  of  band, 
in  service  against  Charleston,  at  the  914th  round,  November  14,  1864. 

Navy  Parrott  100-pounder  rifle  gun,  No.  34,  burst  at  muzzle — used 
against  Charleston  by  army — at  1,225  rounds,  November  12,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  18,  burst  in  front  of  band  and 
band  injured;  used  against  Charleston;  burst  at  454th  round,  November 
15,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  67,  burst  through  breech  and 
band.  The  band  was  broken  into  three  pieces.  The  shell  reached 
Charleston  from  the  gun  in  Fort  Wagner  at  the  round  at  which  the  gun 
burst,  November  15,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  190,  burst  all  in  rear  of  trun- 
nions into  many  pieces,  at  the  102d  round,  in  Battery  Gregg,  November 
28,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  189,  burst  in  front  of  band, 
196th  round;  mounted  in  Battery  Gregg,  November  29,  1864. 

Army  Parrott  100-pounder  rifle  gun,  No.  52,  burst  breech  and  rein- 
force into  many  pieces,  at  1,590th  round;  Battery  Chatfield,  against 
Charleston. 

Navy  Parrott  rifle  trial  giin,  No.  — ,  burst  at  the  420th  round,  15-pound 
charges ;  its  calibre  was  8  inches — 150-pounder. 

Navy  Parrott  rifle  gun,  No.  6,  (150-pouuder,  calibre  8-inch,)  cracked 
in  action,  on  the  monitor  Patapsco. 

Navy  Parrott  rifle  gun,  No.  40,  (calibre  8-inch,  150-pounder,)  cracked 
in  service,  on  the  monitor  Patapsco. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  36,  burst  by  blowing 
off  the  breech,  at  the  226th  round,  on  Morris  island. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  25,  burst  by  blowing 
off  breech,  at  230th  round,  on  Morris  island. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  5,  burst  at  breech,  at 
the  227th  round,  on  Morris  island. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  8,  burst  at  breech,  and 
reinforce,  at  the  522d  round,  on  Morris  island. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  4,  cracked  on  the  out- 
side from  breech  to  trunnion,  at  the  599th  round,  on  Morris  island. 

Army  Parrott  8-inch  rifle  gun,  150-pounder,  No.  6,  burst  at  breech,  at 
the  36th  round,  on  Morris  island. 

Army  Parrott  8-int?h  rifle  gun,  200-pounder,  No.  3,  burst  at  breech,  at 
272d  round.  Shell  reached  Charleston  at  the  round  at  which  the  gun 
gave  way — fired  from  Battery  Chatfield — October  1,  1864. 


214          EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Army  Parrott  8-inch  rifle  gun,  200-pounder,  No.  — ,  burst  in  breech., 
band,  and  reinforce  into  many  pieces,  at  the  1,063d  fire — mounted  in  Bat: 
tery  Gregg — August  15, 1864. 

Army  Parrott  8-inch  rifle  gun,  200-pounder,  No.  24,  at  269th  round 
crack  was  seen  on  the  outside  from  band  to  trunnion,  the  crack  ex- 
tended from  the  inside ;  Battery  Ohatfield,  August  5,  1864. 

Army  Parrott  8-inch  rifle  gun,  200-pounder,  No.  25,  cracked  011  side  of 
breech  outside  and  continued  under  bands  to  trunnion — 578  rounds — July 
30,  1864. 

Army  Parrott  8-inch  rifle  gun,  200-pounder,  No.  20,  burst  at  breech  and 
cracked  inside,  at  1,457th  round,  July  23,  1864. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  6,  cracked  at  muzzle, 
on  Patapsco,  July  22, 1863. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  28,  cracked  on  outside 
around  breech,  rear  of  vent,  on  Shenandoah,  February,  1864. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  46,  cracked  in  bore,  on 
monitor  Onondaga. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  59,  burst  in  chase  and 
muzzle,  on  the  Pequot,  September  12,  1864. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  60,  cracked  on  outside 
from  band  to  trunnion,  on  Colorado,  December  25, 1864. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  61,  cracked  at  vent,  on 
monitor  Onondaga,  April,  1865. 

Navy  Parrott  8-inch  rifle  gun,  150-pounder,  No.  82,  burst,  piece  of 
muzzle  blown  off,  on  Susquehanna,  June  15,  1865. 

Navy  Parrott  8-inch  trial  rifle  gun,  150-pounder,  burst  at  Castle  Island, 
at  the  420th  round — 15-pound  charges  of  powder. 

Army  Parrott  10-inch  gun,  300-pounder,  No.  1,  burst  at  muzzle,  at  the 
27th  round,  on  Morris  island.  This  gun  was  repaired  by  chipping  off  the 
broken  part,  and  burst  again  at  the  37th  round. 

Army  Parrott  30-pounder  rifle  gun,  No.  193,  burst  forward  of  the  band, 
at  the  4,606th  round,  on  Morris  island. 

Army  Parrott  30-pounder  rifle  gun,  No.  — ,  burst  in  breech  and  band 
into  many  pieces,  at  the  2,900th  round,  in  Battery  Gregg,  May  15,  1864. 

Army  Parrott  30-pouuder  rifle  gun,  No.  18,  burst  at  muzzle,  401st 
round,  July  7, 1864. 

Army  Eodman  8-inch  rifle  gun?  burst  December  4, 1865,  at  the  1,047th 
round. 

Army  Rodman  8-inch  rifle  gun,  No.  1,  burst  at  the  80th  round. 

Army  Eodman  12-inch  rifle  gun,  burst  on  the  19th  of  February,  1868, 
at  the  470th  round ;  the  gun  split  through  the  breech  and  reinforce  for- 
ward to  within  four  feet  of  the  muzzle. 

Army  Eodman  12-inch  rifle  gun,  No.  2,  has  been  fired  eight  rounds,  at 
Fort  Monroe,  and  is  reported  injured. 

Army  Eodmau  12-inch  rifle  gun,  No.  — ,  has  been  fired  two  rounds,  at 
Fort  Delaware,  and  is  reported  as  injured. 

Navy  12-inch  rifle,  cast  hollow  on  the  Eodman  system  and  rifled  on 
Mr.  Parrottfs  plan,  burst  at  the  27th  fire. 

Navy  12-inch  rifle  gun,  cast  hollow  on  the  Eodman  system  and  rifled 
on  the  plan  of  General  Eodman,  was  badly  cracked  at  the  16th  round, 
when  firing  stopped. 

Navy  12-inch  rifle,  cast  hollow  and  on  the  Eodman  system  and  rifled 
on  the  Atwater  plan,  burst  at  the  30th  round. 

Navy  15-inch  gun,  in  the  monitor  Miantonomoh,  rjored  four  inches  too 
deep.  Condemnable,  and  to  be  replaced. 

Navy  15-inch  gun,  No.  19,  on  the  monitor  Canonicus,  at  351  fires  "  reports 
contradictory.'1 


EXPERIMENTS  ON  HEAVY  ORDNANCE.  215 

Navy  15-inch  gun,  No.  25,  sold  at  auction  for  cracks  in  the  vent,  9th 
fire. 

Navy  15-inch  gun,  No.  26,  sold  at  auction  for  cavities  in  the  chamber, 
9th  fire. 

Navy  gun  No.  29,  15-inch,  burst  the  Saugus.  This  gun  split  through 
the  breech,  at  Fort  Fisher,  at  the  243d  fire. 

Navy  15-inch  gun,  No.  13,  cracked  in  service,  on  the  monitor  Lehigli. 

Short  15-inch  navy  gun,  No.  24,  surveyed  and  condemned  December, 
1865,  from  monitor  Monadnock,  after  the  168th  fire. 

Short  15-inch  navy  gun,  No.  27,  surveyed  and  condemned  December, 
1865,  from  monitor  Monadnock,  after  the  161st  fire. 

Navy  15-inch  gun,  No.  12,  cracked  at  the  vent  at  the  132d  round,  on 
t&e  monitor  Onandaga. 

Navy  15-inch  gun,  No.  14,  cracked  at  the  vent,  on  the  monitor  Onan- 
daga, at  the  96th  round. 

Navy  15-inch  gun,  No.  1,  (trial  gun,)  burst  at  the  868th  fire. 

Navy  15 -inch  gun,  No.  34,  reported  to  be  in  a  doubtful  condition  after 
fche  363d  fire. 

NOTE. — Of  the  first  34  numbers  of  15-inch  guns  procured  for  the  navy 
for  use  in  the  turrets  of  the  monitors,  12  are  burst  or  disabled.  The 
whole  number  of  rounds  fired  from  all  these  guns  altogether  has  been 
5,448,  equal  to  160  rounds  per  gun. 

Navy  15-inch  gun,  No.  23,  at  358  fires  was  reported  to  be  in  doubtful 
condition ;  it  was  mounted  in  the  monitor  Canonicus. 

Navy  15-inch  gun,  No.  35,  fired  131  rounds  for  proof,  reported  in 
doubtful  condition. 

Navy  15-inch  gun,  No.  44,  on  the  monitor  Mahopac,  split  in  the  chase, 
at  the  85th  round. 

Navy  15-inch  gun,  No.  67,  mounted  on  the  monitor  Puritan,  cracked 
about  the  vent  at  102  rounds,  and  was  sold  at  auction  for  old  iron. 

Navy  15-inch  gun,  No.  68,  cracked  in  the  vent  at  the  59th  round,  and 
was  sold  at  auction  for  old  iron. 

NOTE. — Forty-two  of  the  15-inch  guns  purchased  for  the  navy  have 
never  been  fired  more  than  nine  proof  rounds. 

Of  25  mounted  in  iroii-clads,  which  were  fired  an  aggregate  of  1,333 
fires,  equal  to  an  average  of  53  fires  for  each  gun,  four  have  been  burst 
or  disabled. 

SPONTANEOUS   RUPTURE. 

Navy  11-inch  Dahlgren  gun  found  cracked  at  Eeadiug  foundry,  before 
the  turning  was  completed,  November  10,  1862. 

Navy  11-inch  Dahlgren  gun  cracked  before  the  turning  was  com- 
pleted, November  16,  1862,  at  Reading  foundry,  Pennsylvania. 

Navy  11-inch  Dahlgren  gun  cracked  previous  to  its  completion  at 
Sheading  foundry,  November  16,  1862. 

NOTE. — The  inspector  gravely  attributed  the  premature  rupture  of 
these  guns  to  the  swelling  of  the  sand  of  the  mould  by  heat. 

Navy  gun  15  inch,  (no  number  and  no  date,)  burst  while  cooling,  at  the 
Fort  Pitt  foundry. 

Army  15-inch  Eodman  gun,  No.  404,  made  at  Eeadiug  foundry,  burst 
open  nearly  the  whole  length  while  in  the  lathe.  The  explosion  of  this 
great  gun  was  attended  with  a  loud  report  equal  to  a  six-pounder  gun. 

Army  15-inch  Eodman  gun,  No.  419,  cast  at  Eeading,  Pennsylvania, 
burst  in  the  pit  after  the  removal  of  the  core  barrel. 

Army  15-inch  Eodman  gun  burst  in  the  pit  at  the  Pittsburg  foundry, 
having  split  the  whole  length. 


216  EXPERIMENTS  ON  HEAVY  ORDNANCE. 

Two  army  Rodman  10-inch  guns  cracked  in  the  lathe. 
One  army  Rodman  10-inch  gun,  cast  hollow  and  cooled  from  the. 
interior,  burst  in  the  lathe. 

MISCELLANEOUS. 

Naval  wrought-iron  gun,  80-pounder,  made  at  Reading  by  Syfert, 
McManus  &  Co.,  was  paid  for  February  8, 1864,  the  price  being  $5,607  86 
for  the  forged  block,  to  be  finished  at  the  Washington  navy  yard.  While 
being  finished,  a  flaw  in  the  bore  and  another  in  the  left  trunnion  were 
discovered.  The  gun  was  never  submitted  to  test. 

Two  army  Ames  guns,  7-inch  calibre,  made  of  wrought  iron,  burst  in 
proof. 

Army  Ames  gun,  7-inch  calibre,  bored  out  to  eight  inches,  burst  at 
Fort  Monroe,  at  the  26th  round,  after  the  enlargement. 

Army  Rodman  gun,  13-inch  calibre,  burst  on  the  27th  July,  1864,  at 
the  738th  round.  The  gun  broke  through  the  breech  and  reinforce  into 
a  number  of  pieces. 

Navy  Ericsson's  13-inch  smooth-bore  wrought-iron  gun,  made  at  a  cost 
of  $30,000,  and  paid  for  previous  to  test,  was  fired  40  rounds.  The 'gun 
was  reported  unserviceable. 

A  navy  13-inch  Dahlgren  gun,  cast  solid,  at  Providence,  burst  at  the 
172d  round. 

One  or  two  other  13-inch  guns,  made  for  the  navy,  showed  but  low 
endurance,  but  the  committee  have  not  been  able  to  obtain  particulars. 

Wiard's  15-inch  navy  gun,  of  cast-iron,  first  of  the  class,  burst  at 
Trenton,  with  a  charge  of  80  pounds  of  fine  quick  burning  powder  and  a 
solid  shot  of  886  pounds'  weight.  The  gun  was  improperly  cooled,  by 
which  a  lengthwise  tension  was  inaugurated  sufficient  almost  to  break 
the  gun  before  firing.  The  muzzle  broke  off  before  the  shot  had  reached 
the  point  of  fracture,  as  was  shown  by  the  shot  having  struck  the  frac- 
tured surface  as  it  passed.  The  second  gun,  cooled  differently,  was  never 
fired.  The  bureau  annulled  the  contract  (which  provided  for  two  or 
more  trials)  before  the  second  gun  was  tested. 

The  Whitworth  80-pounders,  built  up  guns,  mounted  on  Morris's 
island,  were  disabled,  each,  at  the  lllth  round,  by  the  lengthening  of  the 
inner  tube,  which  protruded  at  the  breech  one  inch  in  each  case  and  shut 
off  the  vent.  One  of  these  had  a  crack  in  the  exterior  coil  of  the  reinforce. 

Navy  11-inch  gun,  No.  1,  exhibited  cracks  early  during  the  proof,  which 
extended  to  a  length  of  24  inches  at  the  1,958th  fire,  and  it  burst  at  the 
1,959th  round  into  three  great  pieces,  the  fracture  running  through  the 
centre  from  the  breech  and  branching  off  to  either  side  forward  of  the 
trunnions. 

Two  navy  Dahlgren  80-pounder  rifles  were  condemned  as  unservice- 
able, and  sold  at  auction  for  old  iron. 

Thirteen  50-pounder  naval  Dahlgren  rifle  guns,  and  13  30-pounders  of 
the  same  kind,  were  condemned  and  sold. 

Naval  Dahlgren  30-pounder  rifle,  No.  54,  cast  solid  at  Washington 
navy  yard,  burst  at  34th  round. 

Navy  Dahlgren  80-pounder  rifle,  cast  solid  at  Fort  Pitt  foundry,  burst 
at  the  377th  fire ;  was  made  of  cold-blast  charcoal,  iron. 

Navy  Dahlgren  80-pounder  rifle,  cast  solid  at  Fort  Pitt  foundry,  burst 
at  the  852d  fire. 

Navy  Dahlgren  50-pounder  rifle,  cast  solid  at  Cornwall  furnace,  burst 
at  the  204th  fire. 

Naval  Dahlgren  30-pounder  rifle,  No.  49,  cast  solid  at  navy  yard,  Wash 
ington,  burst  at  the  742d  fire. 


EXPERIMENTS  ON  HEAVY  ORDNANCE.          217 

Six  navy  Dahlgren  150-pounder  rifle  guns  were  sold  at  auction  for  old 
iron. 

Navy  Dahlgren  7J-inch  rifle-gun,  150-pounder,  burst  at  the  27th  round. 

Navy  Dahlgren  7£-inch  rifle,  150-pounder,  fired  75  rounds,  reported 
unsatisfactory ;  test  not  continued. 

Navy  Dahlgren  7^-inch  rifle,  150-pounder,  fired  60  times,  reported 
unsatisfactory ;  test  not  continued. 

SUMMARY  OF  BURST  GUNS. 

Parrott  100-pounders,  (rifles) 60 

Parrott  150-pounders,  (8-inch  rifles) ' 22 

Parrott  10-inch  rifles 1 

Parrott  30-pounders 3 

Hodman  12-inch  rifles 4 

Eodman  8-inch  rifles 2 

Eodman  15-inch  smooth-bore,  (navy) 17 

Eodman  13-inch  smooth-bore,  (army) 1 

Dahlgren  150-pounders,  (rifles) 3 

Dahlgren  80-pounders,  (rifles) 2 

Dahlgren  50-pounders,  (rifles) 1 

Dahlgren  30-pounders,  (rifles) 2 

Dahlgren  80-pounders,  (condemned) 2 

Dahlgren  50-pounders,  (condemned) 13 

Dahlgren  150-pounders,  (condemned) 6 

Dahlgren  13-inch  smooth-bore 1 

Dahlgren  11-inch  smooth-bore 1 

Miscellaneous  wrought  and  cast-iron 9 

150 

Burst  spontaneously 10 

Cracked,  fissured,  or  ruptured  before  proof 98 

258 

Eighteen  Parrott  100-pounders,  in  addition  to  the  above,  are  unac- 
counted for,  supposed  to  be  burst. 

Twenty-seven  Parrott  150-pounders  were  condemned  by  the  navy. 

Of  43  Eodman  15-inch  guns,  cast  for  the  navy,  which  was  the  great- 
est number  in  service  at  any  one  time,  17  have  burst  or  been  disabled. 

Of  three  12-inch  Eodman  rifles,  cast  for  the  navy,  one  was  rifled  on 
the  plan  of  Mr.  Parrott  and  burst  at  the  27th  fire ;  one  on  the  plan  of 
Atwater,  burst  at  the  30th  fire :  one  on  the  plan  of  Eodman,  burst  at 
the  16th  fire. 

Of  four  Dahlgren  150-pounder  rifles  one  burst  at  the  27th  fire,  one 
at  the  20th  fire,  one  at  the  75th  fire,  and  one  at  the  60th  fire. 

One  13-inch  gun,  cast  solid,  at  Providence,  endured  178  fires. 

One  13-inch  gun,  cast  hollow,  at  Pittsburg,  endured  108  fires. 

The  navy  15-inch  guns  cast  on  Eodman's  plan  are  divided  by  Admiral 
Dahlgren  into  three  classes : 

1.  The  original  Dahlgren  model. 

2.  The  same  altered  by  Captain  Wise. 

3.  The  new  model  by  Captain  Wise. 

Of  the  first  class  34  were  cast,  17  were  altered  to  the  second  class. 
Of  these  eight  were  disabled — nearly  Aa(/-— after  enduring  but  an  average 
of  135  fires  for  each. 

Eep.  No.  266 15 


218  EXPERIMENTS  ,ON   HEAVY   ORDNANCE. 

One-fifth  of  the  unaltered  guns  were  disabled  after  an  average  of  175 
fires  for  each  gun. 

Sixty-six  guns  were  cast  of  the  third  class.  The  trial  gun  endured 
but  131  fires  when  it  was  disabled. 

Of  the  remaining  65,  40  have  only  been  fired  the  nine  proof  rounds ; 
25  have  been  mounted  in  iron-clads  and  have  been  altogether  fired  1,333 
times ;  one  burst,  three  condemned,  two  of  them  sold  as  old  iron.  One- 
fifth  of  these  failed,  being  subjected  to  an  average  of  53  fires  each. 

NOTE. — The  guns  above  enumerated  are  all  the  15-inch  Rodman  guns, . 
which  have  been  fired  in  service,  none  of  the  army  guns  having  been  so 
fired. 

The  Eodmau  gun  was  first  officially  adopted  in  1862,  by  the  ordnance 
board  of  which  the  inventor  and  patentee  was  a  member.  When  General 
Dyer  became  Chief  of  Ordnance,  in  the  fall  of  1864,  one  of  his  first  acts 
was  to  appoint  General  Rodman  constructor  of  ordnance.  He  raised 
the  price  of  the  15-inch  gun  to  $7,000,  which  was  previously  $6,500,  and 
issued  an  order  to  receive  the  guns  made  under  the  supervision  of  the 
constructor  without  subjecting  tliem  to  the  powder  proof.  Thus  it  can  be 
seen  that  General  Rodman  has  held  in  succession  tbree  important  posi- 
tions in  relation  to  the  reception  of  his  guns,  one-twelfth  of  the  whole 
price  of  which  he  has  received  as  royalty,  viz  : 

1st.  Inventor  and  patentee  while  an  officer  of  the  United  States  army, 
and  of  the  ordnance  corps. 

2d.  A  member  of  the  ordnance  board — the  power  behind  the  throne — 
which  adopted  his  invention  officially  for  the  service  of  the  United  States. 

3d.  Constructor  of  ordnance,  charged  with  the  inspection  and  recep- 
tion of  the  guns  in  which  he  is  interested  as  patentee,  receiving  a* 
royalty.  Two  hundred  and  ninety-six  15-inch  guns  have  been  received 
by  the  army  ordnance  department  under  this  organization.  Twelve 
hundred  and  thirty-three  10-inch  Rodman  guns,  and  155  8-inch,  for  which 
carriages  and  a  large  supply  of  projectiles  have  been  purchased. 

There  is  no  data  upon  which  to  found  an  opinion  that  the  Rodman 
gun,  if  subjected  to  service  test,  would  have  any  special  rate  of  endur- 
.ance.  None  of  them,  except  those  referred  to  above  as  used  in  the  navy, 
have  been  fired  in  battle  or  service.  A  large  proportion  of  them  have 
ibeen  mounted,  without  having  been  fired  at  all. 

The  siege  and  sea-coast  guns  purchased  by  the  army  Ordnance  Office 
from  the  1st  July,  1861,  to  June  30,  1866,  cost  $5,354,365  57 ;  of  this 
.amount  $708,554  20  was  paid  for  Parrott  guns.  The  rest  of  this  amount 
was  paid  principally  for  Rodman  guns ;  $3,230,526  32  was  paid  for  Par- 
srott  projectiles ;  $289,105  80  was  paid  to  Mr.  Parrott  for  carriages  for 
Ms  100-pounders,  200-pounders,  and  300-pounders. 

The  navy  purchases  from  the  Fort  Pitt  foundry,  where  the  Rodman 
.guns  were  principally  made,  amounted  to  $2,116,052  62. 

The  navy  purchases  from  Mr.  Parrott  have  not  been  ascertained.  It 
as  believed  that  more  than  175  100-pounder  guns  were  obtained.  The 
number  of  the  Dahlgren  shell-guns  which  have  been  cracked  or  fissured 
.inside  previous  to  proof,  or  during  experiments  or  service,  could  not  be 
learned.  The  chief  of  the  bureau  evaded  the  questions  relating  to  the 
i)ad  qualities  of  his  own  invention,  while  he  was  elaborate  in  his  answers 
as  to  the  bad  qualities  of  the  guns  of  other  inventors. 


EXPERIMENTS   ON   HEAVY   ORDNANCE.  219 

EXPLANATION  OF  DIAGRAMS. 

PLATE  I  illustrates  the  fractures  usually  occurring  in  guns,  which  are 
of  six  descriptions,  viz : 

1.  Eupture  through  the  breech,  along  the  reinforce,  branching  to  either 
side  forward  of,  or  at,  the  trunnions,  as  shown  in  Fig.  1.    This  fracture 
is  sometimes  accompanied  by  cross  fractures  of  the  reinforce. 

2.  Eupture  at  the  muzzle,  as  shown  in  Fig.  2. 

3.  Eupture  caused  by  the  blowing  out  of  the  breech,  as  shown  in 
Fig.  3. 

4.  Eupture  in  banded  guns,  by  which  a  slab  is  blown  off  the  side  ot 
'the  gun  forward  of  the  band,  as  shown  in  Fig.  4. 

5.  Cracks  on  the  exterior  of  the  gun,  as  shown  in  Fig.  5. 

6.  Cracks  in  the  interior  of  guns.     (Not  shown  by  diagram.) 

PLATES  II,  III,  and  IV  illustrate  the  general  direction  of  fracture  in 
unbanded  guns,  cast  hollow  and  solid,  and  of  the  old  and  new  models. 
Figs.  1  and  2,  Plate  II,  represent  interior  and  exterior  lines  of  frac- 
tures in  a  hollow-cast  10-inch  Columbiad,  old  model.  Fig.  1,  Plate  III, 
shows  the  line  of  fracture  in  a  hollow-cast  of  improved  model,  and  Fig. 
2  the  line  of  fracture  in  a  solid-cast  gun  of  old  model.  Fig.  1,  Plate 
IV,  represents  the  latest  improved  model  of  a  Eodman  hollow-cast  gun. 
Figure  2  represents  a  burst  13-inch  gun  of  the  same  kind,  showing  the 
general  direction  of  fracture  to  be  the  same  as  in  the  preceding  diagrams. 

PLATES  V  and  VI  illustrate  the  cause  of  rupture,  as  shown  by  the 
direction  of  fractures,  supposed  to  result  from  the  combined  effect  of 
pressure  and  unequal  heating.  (See  evidence  of  General  Eodrnan,  Gen- 
eral Gilinore,  and  Norman  Wiard. 

PLATE  VII  illustrates  the  difference  in  the  texture  and  strength  of  iron, 
caused  by  difference  in  the  rate  of  congelation  when  cast. 

PLATES  VIII  and  IX  represent  the  Eodman  external  and  internal 
pressure  metres. 

PLATE  X,  fractures  of  guns  at  the  breech.  Fig.  1,  Whitworth 
80-pounder  gun,  with  inner  tube  extended  and  protruding  one  inch  at 
the  breech.  Fig.  2,  Parrott  200-pounder  gun,  with  breech  blown  out. 
Fig.  3,  Armstrong  300-pounder,  with  breech  blown  out.  Fig.  4,  perspec- 
tive view  from  the  rear  of  same  gun  after  the  accident. 

PLATE  XI  illustrates  fissures  and  differences  of  texture  in  wrought 
iron.  Figs.  1,  2,  3,  and  4  show  fissures  resulting  from  unequal  cooling. 
Fig.  5,  crystallized  wrought  iron.  Fig.  6,  fibrous  wrought  iron.  (See 
evidence  of  Norman  Wiard,  and  Appendix  D.) 

PLATE  XII  represents  the  Ames  wrought-iron  gun,  and  shows  the 
method  of  building  up  the  gun  by  welding  together  a  succession  of  cross 
sections. 

PLATES  XIII  and  XIV  illustrate  the  method  of  fabricature  and  mount- 
ing of  guns  proposed  by  Norman  Wiard,  designed  to  provide  for  restrain- 
ing the  force  of  pressure  and  unequal  expansion,  and  to  cause  the  recoil 
to  be  in  the  direction  of  the  plane  of  the  axis  of  the  bore. 

PLATE  XV,  experimental  castings  illustrating  the  effect  of  unequal 
cooling  on  cast-iron.  (See  evidence  of  Norinan  Wiard.) 


Plate  I 


Tlg.l 


Fig.  3. 


n 


rig.  4. 


Fig.  5. 


Plate  II 


Plate  III 


Fig    2 


Plate  IV 


MEDIUM    13    INCH    RODMAN    CUN 


flan 


r    i 


Plale  V 


Fig.  1 


Fig  2 


FigS 


Fig  5 


Fig  6 


Fig  4 


iff.  7. 


Plate  YI 


8  Inch.  Columbiad. 


Kgl 


Fig    2 


PlatcTII 


DIFFERENCES  OF  TEXTURE  IN  CAST  IRON. 
J)a&  to  differences  in/  the  rat&^of 'congelation;  of  the/  same  irons, 
whew  cast  w  different  sizes  of  mass. 

BY  NORMAN    WIARD 


r,g  2 


Figl 


Fig.  4 


Fig 


Fig.  1.  cas-t  2  inches  diameter,  tensile  strength  '28,000 

Fy.   t.     .    4      ..  .  "  "  22,000 

Fiq   3.     „    8       „  n  .  ,  MOOO 

R     4      .    12      ,,  ,  16.000. 


Plate  VIII. 


17 3. 


Plate  IX 


RODMAN    INTERNAL    PRESSURE   INSTRUMENT 


.Section  on  A  B. 


Seclio/1  on  C.D. 


Fitf.3. 


Plate  X 


Plate  XI 


•  .,;;.^-    -,::-v 


Fig  1 

o 


Fig3 


> 


Fitf.  (> 


Plate  XII 


Plate  :xm. 


Elevation 

or 

200  PS."  WIARD   RIFLE 
Solid 


Section/  on/  ss. 


Section/  oiv  tt. 


DETAILS. 

Combined  JHfle  and  Smooth/ -tort*. 
200   PB-*   WIARD 

wA.    CaLSin, 


Plate  XIV. 


Plate  XV 


• 


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